Add assumption to test

SmsManager.isImsSmsSupported() requires
the FEATURE_TELEPHONY_MESSAGING feature.

This commit adds an assumption to disable
the test on environments lacking this feature.

Bug: 374010452
Flag: EXEMPT, test only change
Test: atest BluetoothMapbMessageSmsTest
Change-Id: Id30ef44afdeaa7ed5d95207c806d400f01fcb60f