Add equals method

This adds an equals method which will for now only be used in tests.

Test: atest BackgroundStartPrivilegesTest
Flag: EXEMPT test only
Bug: 322159724
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:8aef21b72dca756458d25a42599779997d199f09)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f6f2d41ffcd246afb758042b8fdbca9b5775c579)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:815cca137f84295c6037fd04e9de8011392a0ca6)
Merged-In: Ia726fa205b73a693fee775e4a08950ecd4b5f882
Change-Id: Ia726fa205b73a693fee775e4a08950ecd4b5f882