In some cases a sms acknowledgement might be lost. The network will then resend
the same sms. These duplicate sms should be acknowledged but not shown to the
user.
C.S0015-B 4.3.1.6 Unique Message Identification.
The fields used to identify a message are:
* Message Identifier,
* Originating Address,
* Originating Subaddress, and
* Message Center Time Stamp.
Since some of the fields are optional, the Teleservice Layer shall use as
many of the fields as are present in the SMS message to determine message
uniqueness. Mobile stations should discard repeated messages.
1. Add a fingerprint function to SmsMessage.java. This returns a byte array
to be used as a unique identifier. Parts that make up the identifier are
the originating address, teleservice id and the bearerdata. Using all of
the bearerdata saves parsing time. There are no random bits allowed in
the standard. This makes binary comparison possible. Using all of the
bearerdata accounts for the message id, smsc timestamp and "... shall
use as many of the fields as are present in the SMS message".
2. Have CdmaSMSDispatcher.dispatchMessage() pull a fingerprint and check if
it matches the last acknowledged fingerprint. When it matches return and
signal that message was handled.
3. Have CdmaSMSDispatcher.acknowledgeLastIncomingSms() take the last
dispatched fingerprint move it to the last acknowledged fingerprint.
Only do this if processing of the sms was successful.
Change-Id: If79f8fe40896cd290940b7ccd5a17531ab937b60
9d34319f1c