Fix ComponentName mismatch between onCreate() and AndroidManifest

Previously, the creation of
PackageManagerSpammingMediaRoute2ProviderService would crash with an IAE
because the ComponentName it was trying to toggle was not present in the
AndroidManifest.

Bug: 323575695
Test: atest MediaRouter2HostSideTest
Change-Id: I0b78c65fe213c626702efcd7f5a0eaccab5976c3