Make read restricted stats accessible to shell

Make READ_RESTRICTED_STATS permission available to Shell to allow
testing it in gts.

Is the minimally scoped permission that needs to be added?
Yes, it is the only permission needed for the query api.

Test: atest GtsStatsdHostTestCases
Bug: 268248219
Change-Id: Ib6da0aa23a67fed3e62bc2adef3e43914fd39c1c
Merged-In: Ib6da0aa23a67fed3e62bc2adef3e43914fd39c1c