Consider dropping `android:screenOrientation` parameter

[wzieba]

Expected behavior

No activity in AndroidManifest.xml files has android:screenOrientation

Actual behavior

Some activities have defined either landscape or portrait modes. Citing Android Lint documentation:

Should not restrict activity to fixed orientation. This may not be suitable for different form factors, causing the app to be letterboxed.

Steps to reproduce the behavior

Remove DiscouragedApi issues from baseline and run a lint task (after #21082 is merged).