manifest: use forked prebuilts/build-tools

Change-Id: I2b7dd3e854bcd9d0e8e1b72f0694ef61fa07ee13

omni-aosp.xml

@@ -83,6 +83,8 @@
   <project path="packages/services/Telephony" name="android_packages_services_Telephony" remote="omnirom" revision="android-9.0" />
   <project path="packages/services/Telecomm" name="android_packages_services_Telecomm" remote="omnirom" revision="android-9.0" />
 
+  <project path="prebuilts/build-tools" name="android_prebuilts_build-tools" remote="omnirom" revision="android-9.0" />
+
   <project path="system/bt" name="android_system_bt" remote="omnirom" revision="android-9.0" />
   <project path="system/core" name="android_system_core" remote="omnirom" revision="android-9.0" />
   <project path="system/extras" name="android_system_extras" remote="omnirom" revision="android-9.0" />

remove.xml

@@ -144,6 +144,8 @@
   <remove-project name="platform/packages/services/Telephony" />
   <remove-project name="platform/packages/services/Telecomm" />
 
+  <remove-project name="platform/prebuilts/build-tools" />
+
   <remove-project name="platform/system/bt" />
   <remove-project name="platform/system/core" />
   <remove-project name="platform/system/extras" />