Grant shell QUERY_USERS and MODIFY_QUIET_MODE

Added a new permission QUERY_USERS, granted the
new permission and MODIFY_USERS to shell.
These permissions are required to enable CTS
tests to access the following APIs:
* UserManager#getUsers and any other API that depend on it
* UserManager#getProfileParent
* UserManager#requestQuietModeEnabled

Test: Confirmed that a CTS test can call these APIs
Bug: 178695365
Change-Id: Ifa14d24ee1873161e3986e8d0669fd47a7bcaa7a