Replacing build time only Slog's in IMMS with protolog

Currently, there are many Slog.d logs which are compiled out, if
DEBUG=false. To be able to enable logs without recompiling, this CL
replaces those logs with protologs.

Bug: 393561240
Flag: EXEMPT logs only
Test: Enable logs manually via: adb shell cmd protolog logcat enable IMMS_DEBUG
Change-Id: I2c9db3bc4c1e734fa0c643929cbdf1ef006b7cdb