Enhance Mms connectivity tracker workflow

1. Fix Bug 1691499 by a more appoperiate broadcast
and revert 82f5492b211f51e71c7089eb7779384ff03c0d89.
Broadcast CONNECTIVITY_ACTION is more low-frequencyer
and aproprater than ACTION_ANY_DATA_CONNECTION_STATE_CHANGED.
Root cause of Bug# 1691499 is receiving a high-frequencyer
broatcast and not adding a apropriate filter.

2. Reduce useless duration between hanging up and processing Mmes.
Check mms connectivity is available before retried to connect.

3. Using getNetworkInfo instead of the deprecated one
4. Remove useless codes and make ConnectivityBroadcastReceiver
more readable.

Change-Id: I994d3cccead1e43865c42a24e20021321e140686
Signed-off-by: Roger Chen <cxr514033970@gmail.com>

Conflicts:

	src/com/android/mms/transaction/MmsSystemEventReceiver.java
	src/com/android/mms/transaction/TransactionService.java