Check service before calling it

AuthenticationPolicyService is not available on watch, TV and auto. So
ServiceNotFoundException can be thrown on these devices via
BiometricService.Injector#getAuthenticationPolicyManager

Fixes: 423599294
Test: atest WatchRangingHelperTest
Flag: EXEMPT bug fix
Change-Id: I1c63538781061b97c492e1b3b895958f2403b8f5