DO NOT MERGE ANYWHERE: Revert "add repohooks"

This reverts commit 12da222884.
After more discussion, we're going to take a
different approach to handling the repo hooks
(splitting into two repositories so the hooks
can be easily modified without triggering more
spam from repo), so reverting for now.
Bug: 28295071
Change-Id: I948ac019f0a95101f04a9ef4d4070079dea4b4ad
Test: None

default.xml

@@ -536,12 +536,9 @@
   <project path="tools/idea" name="platform/tools/idea" groups="notdefault,tools" />
   <project path="tools/loganalysis" name="platform/tools/loganalysis" groups="notdefault,tradefed" />
   <project path="tools/motodev" name="platform/tools/motodev" groups="notdefault,motodev" />
-  <project path="tools/repohooks" name="platform/tools/repohooks" />
   <project path="tools/studio/cloud" name="platform/tools/studio/cloud" groups="notdefault,tools" />
   <project path="tools/swt" name="platform/tools/swt" groups="notdefault,tools" />
   <project path="tools/test/connectivity" name="platform/tools/test/connectivity" groups="pdk" />
   <project path="tools/tradefederation" name="platform/tools/tradefederation" groups="notdefault,tradefed" />
 
-  <repo-hooks in-project="platform/tools/repohooks" enabled-list="pre-upload" />
-
 </manifest>