Set updateable:false explicitly in apex rules.

Currently, this is the default so this is a no-op,
But the default is changing to true.

Bug: 180375550
Test: Treehugger
Change-Id: I153e6f842e03a732bfa852b830e0f65050e9270f

core/tests/overlaytests/remount/test-apps/overlaid_apex/Android.bp

@@ -39,4 +39,5 @@ apex {
     key: "com.android.overlaytest.overlaid.key",
     apps: ["OverlayRemountedTest_Target"],
     installable: false,
+    updatable: false,
 }

core/tests/overlaytests/remount/test-apps/overlay_apex/Android.bp

@@ -39,4 +39,5 @@ apex {
     key: "com.android.overlaytest.overlay.key",
     apps: ["OverlayRemountedTest_Overlay"],
     installable: false,
+    updatable: false,
 }

tests/RollbackTest/Android.bp

@@ -96,6 +96,7 @@ apex {
   key: "com.android.apex.apkrollback.test.key",
   apps: ["TestAppAv1"],
   installable: false,
+  updatable: false,
 }
 
 apex {
@@ -106,6 +107,7 @@ apex {
   key: "com.android.apex.apkrollback.test.key",
   apps: ["TestAppAv2"],
   installable: false,
+  updatable: false,
 }
 
 apex {
@@ -116,4 +118,5 @@ apex {
   key: "com.android.apex.apkrollback.test.key",
   apps: ["TestAppACrashingV2"],
   installable: false,
+  updatable: false,
 }
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