Update *EmergencyNumberDb*() feature flag dependency

Given that  *EmergencyNumberDb*() functionality is utilized by both
calling and messaging modules, and messaging can be enabled without
calling, the function's access control should be based on FEATURE_TELEPHONY and
not FEATURE_TELEPHONY_CALLING.

Bug: 395178686
Flag: EXEMPT bug fix
Test: atest CtsTelephonyTestCases --no-bazel-mode
Change-Id: I4da90c5f78a0fcbdb5b56d90aad43e0f696dc6c1