Do not retry forever in DataConnection.

When we are initially to connect we limit the the number of
retries so as to go through the list of waiting apns. But if retry
forever is enabled, as it is with Verizon devices, we can burn the
battery down quickly because we're retrying with short initial
timeouts.

In this change I also increase the timeout between apn retries from
5 seconds to 20 seconds to further reduce battery drain when retrying.
And added a retry with a longer timeout if to keep the contract with
ConnectivityService that when enabled we will continue to retry.

Bug: 9240744
Change-Id: I45b9ec5300d602d838dbdeacdbd1fca0c4d65ee3