Modify UidRecord.CHANGE_PROCSTATE such that it behaves like a bit mask.

UidRecord.CHANGE_PROCSTATE was allocated the value 0, since it is
assumed that if there is any change to a UidRecord it includes a proc
state change. This is a valid assumption, but is not an unusual design
for a bitmask. This change adds a bit specifically for proc state
changes.

At the time of this change, CHANGE_PROCSTATE should always be set.
However the intention is to pre-empt change
I68d964f474d20f819f54b614a4e314ce00aac8fb, which breaks the assumption
that all UidRecord changes will include proc state. To avoid verbosity,
additional constants have been defined which combine the other change
bits with CHANGE_PROCSTATE for external users to reference.

Change-Id: Iae7e6601938d1b3ee5c4c9b339ae06029eb598e6
Bug: 124224342
Test: -- ActivityManagerServiceTest
      -- ActivityManagerProcessStateTest
      -- ActivityManagerFgsBgStartTest
      -- UidObserverControllerTest
      -- CtsAppTestCases