Check voice support using TelephonyManager.isDeviceVoiceCapable()

The isVoiceCapable() method in TelephonyManager, which relied
exclusively on checking the config_voice_capable config setting is now
deprecated. The config_voice_capable config setting is itself
deprecated since VENDOR_API_2024_Q2.

On newer vendor API levels, the isDeviceVoiceCapable() method uses the
new FEATURE_TELEPHONY_CALLING PackageManager flag to report whether a
device is voice capable or not.

NO_IFTTT=Underlying unit tests don't require an update.

Bug: 395714454
Test: mm && atest SettingsRoboTests
Flag: EXEMPT bugfix
Change-Id: I9ba202ded585e64f39391dc557863e26f2f25864