Add a timeout in waiting state to unblock the state machine after 30s.

This is so that if the state machine is stuck in waiting state, the
current message can be dropped and other messages can still be
processed.

Test: manual with hacks to make state machine be stuck in waiting
state
runtest --path
frameworks/opt/telephony/tests/telephonytests/src/com/android/
internal/telephony/gsm/GsmInboundSmsHandlerTest.java
--test-method testWaitingStateTimeout
Bug: 65599291
Change-Id: Ib944b28023c1225d6db8945b56eff8996d0a0248