android root: restore context for android system root

In this patchset we will store and reset the android system
root context after a wipe and restore to prevent issues
with no context labels in the file_contexts being applied.
This will prevent no boot issues in android with selinux
denials on the system root partition.

Change-Id: I87fd3a6060fbaa3e7bdfd7a4b1d09feeb4fa3f27
(cherry picked from commit 35d2bfda3c89ebd212a9bd2328bffd7464f95d47)
diff --git a/gui/theme/common/languages/en.xml b/gui/theme/common/languages/en.xml
index d8bf2c5..846339d 100755
--- a/gui/theme/common/languages/en.xml
+++ b/gui/theme/common/languages/en.xml
@@ -751,5 +751,6 @@
 		<string name="rescue_party2"> 2. Format data, and/or</string>
 		<string name="rescue_party3"> 3. Clean-flash your ROM.</string>
 		<string name="rescue_party4">The reported problem is: </string>
+		<string name="restore_system_context">Unable to get default context for {1} -- Android may not boot.</string>
 	</resources>
 </language>