Set device orientation for tests.

Some tests were failing in the lab based on device orientation:
In landscape mode, the TextView goes into ExtractEditTextMode.
This mode behaves a bit differently from typical TextView mode
and doesn't support accelerated drag selection (e.g. longpress+drag).

This CL adds OrientationUtil that allows test to specify the
orientation (portrait/landscape) that the test should run in.
This CL also fixes the failing tests.

Bug: 24495166
Change-Id: I2f9372997f8301d800109981c6e1a6d4419b641d