Rename the enums that are supposed to match OBD2 values to have an Obd2 prefix

Rename the enums that contain a list of sensors and don't directly map to OBD2 to have a Diagnostic prefix

Test: clean build and flash, then
runtest -x packages/services/Car/tests/android_car_api_test/src/android/car/apitest/CarDiagnosticManagerTest.java
runtest -x packages/services/Car/tests/carservice_test/src/com/android/car/test/CarDiagnosticManagerTest.java
runtest -x packages/services/Car/tests/vehiclehal_test/src/com/android/car/vehiclehal/test/Obd2FreezeFrameTest.java
runtest -x packages/services/Car/tests/vehiclehal_test/src/com/android/car/vehiclehal/test/Obd2LiveFrameTest.java

Bug: 64024685
Change-Id: I9147bcd8f2972dee9f3d1e62f8978b595d88f606