Remove LOCAL_PROGUARD_ENABLED := nosystem

None of the system options are controversial, and there are no
longer any users of nosystem, so remove it.

Test: m checkbuild
Change-Id: Id1b946d83688d266ca2942c02c97e8b404c3755b
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 06518ee..e9c07df 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -194,7 +194,7 @@
 LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES:=
 LOCAL_PREBUILT_STRIP_COMMENTS:=
 LOCAL_PRIVILEGED_MODULE:=
-# '',full,custom,nosystem,disabled,obfuscation,optimization
+# '',full,custom,disabled,obfuscation,optimization
 LOCAL_PROGUARD_ENABLED:=
 LOCAL_PROGUARD_FLAG_FILES:=
 LOCAL_PROGUARD_FLAGS:=