Add unit test for PhoneAccount equality operator.

Test: Add unit test for PhoneAccount equality.
Bug: 112884689
Merged-In: I563d1dfbb1f6c9b20f7b4ecd50b671009451c2c4
Change-Id: I563d1dfbb1f6c9b20f7b4ecd50b671009451c2c4
(cherry picked from commit 78722fde80f8870d226294791543902196a9962a)
(cherry picked from commit 1b05f949002b6dfff830f4879e3cf22c8417b075)
1 file changed