metricstarttimeprocessor: prepare for adding the metricstarttimeprocessor to the contrib distribution (open-telemetry#39858)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
Adds the metricstarttimeprocessor to the contrib build

<!-- Issue number (e.g. open-telemetry#1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes open-telemetry#39857

<!--Describe what testing was performed and which tests were added.-->
#### Testing
Unit tests and integration tests are part of the component.

<!--Describe the documentation added.-->
#### Documentation
Readme as part of the component

<!--Please delete paragraphs that you did not use before submitting.-->

---------

Signed-off-by: Ridwan Sharif <[email protected]>
Co-authored-by: Curtis Robert <[email protected]>

Author: 2 people

.chloggen/add-processor-to-contrib-build.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: processor/metricstarttime
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Upgrade the stability to `Alpha`
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [39857]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

cmd/otelcontribcol/builder-config.yaml

@@ -126,6 +126,7 @@ processors:
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/k8sattributesprocessor v0.125.0
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/logdedupprocessor v0.125.0
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/metricsgenerationprocessor v0.125.0
+  - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/metricstarttimeprocessor v0.125.0
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/metricstransformprocessor v0.125.0
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/probabilisticsamplerprocessor v0.125.0
   - gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/redactionprocessor v0.125.0

processor/metricstarttimeprocessor/README.md

@@ -1,13 +1,14 @@
 <!-- status autogenerated section -->
 | Status        |           |
 | ------------- |-----------|
-| Stability     | [development]: metrics   |
-| Distributions | [] |
+| Stability     | [alpha]: metrics   |
+| Distributions | [contrib] |
 | Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Aprocessor%2Fmetricstarttime%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Aprocessor%2Fmetricstarttime) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Aprocessor%2Fmetricstarttime%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Aprocessor%2Fmetricstarttime) |
 | Code coverage | [![codecov](https://codecov.io/github/open-telemetry/opentelemetry-collector-contrib/graph/main/badge.svg?component=processor_metricstarttime)](https://app.codecov.io/gh/open-telemetry/opentelemetry-collector-contrib/tree/main/?components%5B0%5D=processor_metricstarttime&displayType=list) |
 | [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@dashpole](https://www.github.com/dashpole), [@ridwanmsharif](https://www.github.com/ridwanmsharif) |
 
-[development]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/component-stability.md#development
+[alpha]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/component-stability.md#alpha
+[contrib]: https://github.com/open-telemetry/opentelemetry-collector-releases/tree/main/distributions/otelcol-contrib
 <!-- end autogenerated section -->
 
 ## Description

processor/metricstarttimeprocessor/internal/metadata/generated_status.go

@@ -3,8 +3,8 @@ type: metricstarttime
 status:
   class: processor
   stability:
-    development: [metrics]
-  distributions: []
+    alpha: [metrics]
+  distributions: [contrib]
   codeowners:
     active: [dashpole, ridwanmsharif]
 

processor/metricstarttimeprocessor/metadata.yaml

@@ -104,6 +104,7 @@ components:
         - k8sattributes
         - logdedup
         - metricsgeneration
+        - metricstarttime
         - metricstransform
         - probabilistic_sampler
         - redaction