Restore the OEM hook implementation and usage

The current plan is to keep the OEM hook implementation in the framework
, this is for legacy device and old device upgrading (per b/78098059).

For P launching device, the OEM hook service is removed in hal, so the 
OEM hook api in framework should return something dummy, and prevent 
infinite loop to get service, but these parts should be done in seperate
CLs after this restore CL is merged.

This reverts commit f09bde28.

Bug: 34344851
Change-Id: I2aea9be9aa7cecd4f7a1f1783391f0af173bfc59
Test: pass Treehugger tests; pass cuttlefish test RilE2eTests

Merged-In: I1f2117331a7f846b192c5f956f3841d58cb8154b