twrp-extras: use TeamWin update_engine repo

Change-Id: I2efa3b2ef6399e146ec9f35b63178fe13a4a8da2

twrp-extras.xml

@@ -30,4 +30,8 @@
 
 <!-- Include external Magisk repo for repack binaries -->
     <project path="external/magisk-prebuilt" name="external_magisk-prebuilt" remote="TeamWin" revision="master" />
+
+<!-- Include TeamWin android_system_update_engine to build a good update_engine_sideload -->
+    <remove-project name="android_system_update_engine" />
+    <project path="system/update_engine" name="android_system_update_engine" remote="TeamWin" revision="android-9.0" />
 </manifest>