Implement handling logic of SEND USSD STK command

SEND USSD handling logic is added.

It sends the command to the StkApp, send USSD, and report terminal
response to the SIM with the USSD return result.

Bug: 404099417
Test: FrameworksTelephonyTests
Test: Simulate commands using the test intent
Flag: com.android.internal.telephony.flags.support_stk_command_ussd_and_call
Change-Id: Id20f7e11d1aa443dfd2a01339122bafcf35bded4