Add state BOUND_FGS_OR_TOP and FGS into ProcessState Enum in ProcStats

Previously these two states in AMS are being mapped into the ImpFg
in the ProcStats, we were unable to distinguish them in the aggregated
proc stats. Now with these two new states in ProcStats, the process
states we're using in AMS could be mapped into them, and eventually
get mapped into the state definition in the aggregated proc stats.

Bug: 186438656
Test: atest ProcStatsValidationTests
Test: atest ProcessStatsDumpsysTest
Test: atest CtsIncidentHostTestCases:ProcStatsProtoTest
Test: atest CtsStatsdHostTestCases
Test: atest CtsAppTestCases:ActivityManagerProcessStateTest
Change-Id: I94eaa18d9c99f90200603fd0aafe198b62e963f7