Fix debug logging in the backup service

The existing DEBUG and DEBUG_SCHEDULING had been set to true (maybe
accidentally?) for 8+ years. Whereas MORE_DEBUG is false as expected. In
this CL we:

1) Remove existing DEBUG and DEBUG_SCHEDULING checks. This is a no-op.
2) Rename MORE_DEBUG to DEBUG. Also no-op.
3) Make any Log.v log that isn't guarded by if(DEBUG) a Log.d instead.
   Log.v logs should always be guarded by a default false constant so
   the compiler strips out the Strings from the binary.

Test: n/a
Flag: EXEMPT no-op refactor
Change-Id: I117f7fe04da1a62c3ad42d71b080fed6454f73af