Revert "temp rename failing tests to failingXXX until issues are resolved."

This reverts commit dda37a975c17a03dbf7bf33c5d4ef93c13565440.
Removed test assertions, since they didn't make sense to me.

https://github.com/couchbase/couchbase-lite-android/commit/177b98c3a21572c18875fdcdf3ba502a4c379e5e#commitcomment-5871351
Remove another test assertion that did not make sense.

https://github.com/couchbase/couchbase-lite-java-core/issues/92
It is now expected that doc.getCurrentRevision() will return null for deleted docs

https://github.com/couchbase/couchbase-lite-java-core/issues/92
temporarily disable testContinuousPushReplicationGoesIdle

https://github.com/couchbase/couchbase-lite-ios/issues/301