Remove flakey assertion from testAddSubscription

Remove check on pull thread wakeup count for subscriptions.
The test only uses pushed atom subscriptions so asserting on pull thread
wakeup count isn't needed here. The count can be flakey because it is
incremented in a separate thread at the beginning of the processing
loop.

Bug: 342832813
Test: atest statsd_test:ShellSubscriberCallbackTest.testAddSubscription
Change-Id: I0774065360710a1ed21e2b10a28f2e2115a3014a
1 file changed