Add rebindService API to update binding flags.

This will allow applications to eliminate multiple bindings to handle
the case of needing to increase or decrease priority of service
processes by allowing them to repurpose a single binding.

Bug: 424003130
Flag: android.content.flags.enable_update_service_bindings
Test: atest android.app.cts.service.ServiceTest
Change-Id: I24b01ccc8bf5f15b5fe12efb243430413f3f79d5