Stub out ga_init() in android build

Change-Id: I0c68510ece755fc8e8f4a93e9d6f017fc23fcfee
Signed-off-by: Mike Lockwood <lockwood@google.com>

groupaccess.c

@@ -48,6 +48,9 @@ static char **groups_byname;
 int
 ga_init(const char *user, gid_t base)
 {
+#ifdef ANDROID
+	return 0;
+#else
 	gid_t *groups_bygid;
 	int i, j;
 	struct group *gr;
@@ -70,6 +73,7 @@ ga_init(const char *user, gid_t base)
 			groups_byname[j++] = xstrdup(gr->gr_name);
 	xfree(groups_bygid);
 	return (ngroups = j);
+#endif
 }
 
 /*