76ab5fb247
SubscriptionManager#addOnSubscriptionsChangedListener can fail to register a listener if the TELEPHONY_REGISTRY system service is not up. Currently this is just silently ignored. Adding a callback method on the listener to notify the registrant that the listener failed to be registered, and adding exponential backoff code in TelecomAccountRegistry to retry registration. Test: Manual; edited code in Subscriptionmanager to fail the first attempts to add a listener for TelecomAccountRegistry. Verified the backoff took place and registration still occurred for the listener. Test: Tried to write a mockito test but gave up because this code has far too many intertwined dependencies and is not inherently testable Bug: 152217039 Fixes: 153376310 Change-Id: Icf3133cdeca526979cb621f29659b880127b680a Merged-In: Ib032072dcfd2d3d5e700e380af08b7b3142ebb8e