Remove permission info from CallerIdentity

Location permission info is 1) location specific and 2) may change over
time, and thus shouldn't be in CallerIdentity. This CL moves the
information (temporarily) into LocationRequest. Follow up CLs will
include deeper refactors that eliminate the need for this information to
be in LocationRequest as well.

Test: manual + presubmits
Change-Id: I3b4b41941e386f644efce2effe6985b9c865586c