Rename sdkext sepolicy to sdkextensions

The module is getting renamed, so rename all the policy
relating to it at the same time.

Bug: 137191822
Test: presubmit
Change-Id: Ia9d966ca9884ce068bd96cf5734e4a459158c85b
Merged-In: Ia9d966ca9884ce068bd96cf5734e4a459158c85b
(cherry picked from commit 6505573c36dcc6153af37895e968400f722119ea)
diff --git a/apex/Android.bp b/apex/Android.bp
index 29c2518..1c27bc3 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -28,6 +28,13 @@
 }
 
 filegroup {
+  name: "com.android.sdkext-file_contexts",
+  srcs: [
+    "com.android.sdkext-file_contexts",
+  ],
+}
+
+filegroup {
   name: "com.android.art.debug-file_contexts",
   srcs: [
     "com.android.art.debug-file_contexts",
@@ -133,13 +140,6 @@
 }
 
 filegroup {
-  name: "com.android.sdkext-file_contexts",
-  srcs: [
-    "com.android.sdkext-file_contexts",
-  ],
-}
-
-filegroup {
   name: "com.android.telephony-file_contexts",
   srcs: [
     "com.android.telephony-file_contexts",