SimCallManager can access #getDefaultOutgoingPhoneAccount.

This change allows the sim call manager to access the default outgoing
phone account. This is required to allow the sim call manager to register
incoming calls with the platform without requiring the READ_PHONE_STATE
permission.

Bug: 148111849
Test: TelecomServiceImplTest.java
Merged-In: I4d9a87dab2759d916f8a1bba5f8e4a654d5185e5
Change-Id: I4d9a87dab2759d916f8a1bba5f8e4a654d5185e5
(cherry picked from commit d2d02a35)