Revert "Refactor waitcondition resources to allow easier subclassing"

This reverts commit 850ac0c1b552d2bae91d5718df56c3e3a739b2f5.

One of the prior two commits prior are causing Metadata to come back empty
after signals are processed. This must be reverted because it conflicts
with those commits.

Change-Id: I37c11e3b7e4c7528ebd21736ed4a32288ff4e77e
Partial-Bug: #1337772
Revert "Update waitcondition API to use signal RPC interface"

This reverts commit f2f2697c9d8f926869f93f34c0a6df0df7cba20a.

This and/or the previous commit are causing Metadata to return blank
after signals are processed.

Change-Id: I1c8b3f18e63d9c74b00b27fc32c5d5746faa8235
Partial-Bug: #1337772
Revert "Convert WaitConditionHandle to use handle_signal"

This reverts commit a60f2722f8e084c4d68d2e439c6cc7c1d049b696.

This and/or the next commit (f2f2697c9d8f926869f93f34c0a6df0df7cba20a)
are causing Metadata to return blank after signals are processed.

Change-Id: Ic4e068fd1e26e51e826055cebed6a392a5595bf9
Partial-Bug: #1337772
Merge "Revert "Refactor waitcondition resources to allow easier subclassing""
Merge "Revert "Update waitcondition API to use signal RPC interface""
Merge "Revert "Convert WaitConditionHandle to use handle_signal""