BluetoothManagerService: Remove proto dump

Added by the Android Health team to dump
structured bt stats through the bluetooth_manager
dumpsys on incident reports.

This has now been deprecated and the proto output
can be removed.

Bug: 331817295
Test: m com.android.bt
Flag: EXEMPT, dead code removal
Change-Id: I06b9d6a9937582d2692df7c4e5e59fd24c60d999