Adds @hide ImsResolver API and device overlays (2/3)

- Adds config_ims_package device overlay, which specifies the default
package name to bind to.
- Adds config_dynamic_bind_ims device overlay, which determines
whether or not the new dynamic binding system is used.
- Adds @hide TelephonyManager API to interface with the ImsResolver

Test: Manual
Merged-In: I82a41da00e6da34629a40db431f13b968dfafe2e
Change-Id: I82a41da00e6da34629a40db431f13b968dfafe2e