Adding adb_debug.prop into debug ramdisk

The debug ramdisk can only be used if the device is unlocked.
When it's used, init will load adb_debug.prop and the userdebug
sepolicy from the debug ramdisk, to allow adb root on a user build.

Bug: 126493225
Test: 'make' and checks the file is installed
Change-Id: Id6962414197fc8f47f7c07818e8fb16107dc17a3

init/Android.mk

@@ -65,6 +65,11 @@ LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_MODULE_PATH := $(TARGET_RAMDISK_OUT)
 LOCAL_UNSTRIPPED_PATH := $(TARGET_RAMDISK_OUT_UNSTRIPPED)
 
+# Install adb_debug.prop into debug ramdisk.
+# This allows adb root on a user build, when debug ramdisk is used.
+LOCAL_REQUIRED_MODULES := \
+   adb_debug.prop \
+
 # Set up the same mount points on the ramdisk that system-as-root contains.
 LOCAL_POST_INSTALL_CMD := mkdir -p \
     $(TARGET_RAMDISK_OUT)/apex \

rootdir/Android.mk

@@ -377,4 +377,13 @@ $(LOCAL_BUILT_MODULE):
 	$(hide) $(foreach lib,$(PRIVATE_VNDK_SAMEPROCESS_LIBRARIES), \
 		echo $(lib).so >> $@;)
 
+#######################################
+# adb_debug.prop in debug ramdisk
+include $(CLEAR_VARS)
+LOCAL_MODULE := adb_debug.prop
+LOCAL_SRC_FILES := $(LOCAL_MODULE)
+LOCAL_MODULE_CLASS := ETC
+LOCAL_MODULE_PATH := $(TARGET_DEBUG_RAMDISK_OUT)
+include $(BUILD_PREBUILT)
+
 include $(call all-makefiles-under,$(LOCAL_PATH))

rootdir/adb_debug.prop

@@ -0,0 +1,12 @@
+# Note: This file will be loaded with highest priority to override
+# other system properties, if a special ramdisk with "/force_debuggable"
+# is used and the device is unlocked.
+
+# Disable adb authentication to allow test automation on user build GSI
+ro.adb.secure=0
+
+# Allow 'adb root' on user build GSI
+ro.debuggable=1
+
+# Introduce this property to indicate that init has loaded adb_debug.prop
+ro.force.debuggable=1