Improved ignore-backoff handling

Allow a non-epidited ignore-backoff op to pass through
an expidited backed off op.

To do this, I first refactored the complicated if statement:

            if (best == null
                    || ((bestSyncableIsUnknownAndNotARetry == syncableIsUnknownAndNotARetry)
                        ? (best.expedited == op.expedited
                           ? opRunTime < bestRunTime
                           : op.expedited)
                        : syncableIsUnknownAndNotARetry)) {
                best = op;
                bestSyncableIsUnknownAndNotARetry = syncableIsUnknownAndNotARetry;
                bestRunTime = opRunTime;
            }

Into a more readable:
            boolean setBest = false;
            if (best == null) {
                setBest = true;
            } else if (bestSyncableIsUnknownAndNotARetry == syncableIsUnknownAndNotARetry) {
                if (best.expedited == op.expedited) {
                    if (opRunTime < bestRunTime) {
                        //  if both have same level, earlier time wins
                        setBest = true;
                    }
                } else {
                    if (op.expedited) {
                        setBest = true;
                    }
                }
            } else {
                if (syncableIsUnknownAndNotARetry) {
                    setBest = true;
                }
            }
            if (setBest) {
                best = op;
                bestSyncableIsUnknownAndNotARetry = syncableIsUnknownAndNotARetry;
                bestRunTime = opRunTime;
            }

The refactoring was all done automatically with IntelliJ to avoid human error
in the conversion.

After verifying this code still behaved as expected including the error
condition in the bug, I added handling for the cases when a non-expidited op
may override an expedited op if certain conditions occur, specificaly, if the
expidited op is backed off and the non-expidited op is not.

Finally, refactored to make it testable and added tests and logging.

Bug: 3128963

Change-Id: I131cbcec6073ea5fe425f6b5aa88ca56c02b6598