Remove permission for APEX manifest.

There is no real need to access the manifest.json (which is being
renamed in other CLs anyway). So remove the access to it.

Bug: 119672727
Test: m, installed on device, boots.
Change-Id: I2d82062031da36f871b2a64d97a50a6f1e6fc3dd
diff --git a/apex/apex.test-file_contexts b/apex/apex.test-file_contexts
index 3dffd86..784ad54 100644
--- a/apex/apex.test-file_contexts
+++ b/apex/apex.test-file_contexts
@@ -1,3 +1,2 @@
-/manifest\.json   u:object_r:system_file:s0
-(/.*)?            u:object_r:system_file:s0
-/bin/surfaceflinger u:object_r:surfaceflinger_exec:s0
+(/.*)?                 u:object_r:system_file:s0
+/bin/surfaceflinger    u:object_r:surfaceflinger_exec:s0