Fix watch issues related to absence of WebView control.

CPd from ag/28404901

Refactor HTMLFormatter into a TextFormatter interface with
HTMLFormatter and PlainTextFormatter implementations.

Bug: 354247239
Bug: 353327853
Test: Run CTS-Verifier on watch, run tests. no crashes
Flag: TEST_ONLY
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:8bb9e9e4d898aeee5a56e4ccd4dc54eeb60169da)
Merged-In: Ic423bb199ca32abf25cb7792731f9da93bafccc9
Change-Id: Ic423bb199ca32abf25cb7792731f9da93bafccc9
Combined CTS Verifier audio test updates