[CollapsingToolbarLayout] Expose setExpandedTextSize & setCollapsedTextSize #775
Description
In CollapsingToolbarLayout, if you have a title that could be long, the only way to resize it to fit the available space is to manually calculate the size of the text and then maintain a giant list of alternate text appearance styles, using setExpandedTextApperance to change the text size. This gets even uglier if you want change other text appearance attributes under various conditions.
The collapsingTextHelper already has setExpandedTextSize and setCollapsedTextSize function, but it's package private and restricted. Adding a couple methods to access this through CollapsingToolbarLayout would be trivial and save some major headaches.