Add espresso tests for PhotoPicker

Bug: 168001592
Test: atest
com.android.providers.media.photopicker.espresso.PickerActivityTest

Change-Id: Ib01fbc716416c8362497eb14a6bbc882a3674a3a
Merged-In: Ib01fbc716416c8362497eb14a6bbc882a3674a3a
(cherry picked from commit 99a1c9cd15fa6410d7ccadf17661ddf1201169d9)
3 files changed