Start OBEX Client as a function of supported features

This change migrates the features from a hardcoded value on the client,
to something the owner of the client can define based on the features
they know they have.

Bug: 365626536
Flag: EXEMPT, mechanical refactor
Test: atest com.android.bluetooth.pbapclient
Test: m com.android.btservices
Change-Id: I6f0219593c24fe641893f184a3b8fbdccec2827f