AutoSize TextView (part 1) - minimal end-to-end

Introduced the minimal number of attributes needed
to do autosizing and the autosize functions
bundled in TextView (for now). Note that in this
first version the autosizing can only be controlled
via construction.

Next: introduce getters/setters for the new attributes.

Bug: 32221168
Test: added a minimal smoke-ish CTS which exercises the
      new attributes.

Change-Id: Idf2195f6a600bfb7908b703ea046209b5868c521