remove `-landroid_support`

Copied from https://review.skia.org/128009

Change-Id: I8a73cd13c07887d5e3d0459f4476cfdd80678769
Reviewed-on: https://skia-review.googlesource.com/c/182961
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index 25d9006..512d521 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -160,8 +160,10 @@
     libs += [
       "c++_static",
       "c++abi",
-      "android_support",
     ]
+    if (ndk_api < 21) {
+      libs += [ "android_support" ]
+    }
   }
 
   if (is_ios) {