Mark updatable APEXes

Mark updatable APEXes as updatable: true so that they are opted-out from
optimizations that make sense only for non-updatable modules; such as
symlinking to the libs in the system partition.

Bug: 149805758
Test: m and check that there is no symlink from the APEX to the system
partition.

Change-Id: Idb55300a60a261c7bb6359439ed220ff51fcf06c
diff --git a/apex/sdkextensions/Android.bp b/apex/sdkextensions/Android.bp
index 25765af..322d5e1 100644
--- a/apex/sdkextensions/Android.bp
+++ b/apex/sdkextensions/Android.bp
@@ -26,6 +26,7 @@
 
 apex_defaults {
     name: "com.android.sdkext-defaults",
+    updatable: true,
     java_libs: [ "framework-sdkextensions" ],
     prebuilts: [
         "derive_sdk.rc",