Add METADATA to sl4a: contains GPL is RESTRICTED

Bug: 68860345
Bug: 69058154
Bug: 151953481

Test: no code changes

Exempt-From-Owner-Approval: janitorial work

Change-Id: Id7ff2d9c2abb74979e0b8dabcef3b4d68642e807
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..6d8601b
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,3 @@
+third_party {
+  license_type: RESTRICTED
+}