Compatibility_matrix: s/current/4/

To indicate frozen state/development shouldn't occur here.

Bug: 126892442
Test: TH (build checks compatibility matrices)
Change-Id: I3daf93d750462bf7dcb698a353801bc55a459d45
(cherry picked from commit 86eb7fc62bd138c746e20171124abaf9b975006c)
Merged-In: I3daf93d750462bf7dcb698a353801bc55a459d45
diff --git a/compatibility_matrices/Android.mk b/compatibility_matrices/Android.mk
index 425e376..b0caa7c 100644
--- a/compatibility_matrices/Android.mk
+++ b/compatibility_matrices/Android.mk
@@ -96,7 +96,7 @@
     framework_compatibility_matrix.1.xml \
     framework_compatibility_matrix.2.xml \
     framework_compatibility_matrix.3.xml \
-    framework_compatibility_matrix.current.xml \
+    framework_compatibility_matrix.4.xml \
     framework_compatibility_matrix.device.xml \
 
 my_framework_matrix_deps += \