Reenable x86 builds (#476)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/476

Fixes https://github.com/facebook/flipper/issues/471

Disabling the x86 builds altogether does more harm than good.

Reviewed By: jknoxville

Differential Revision: D16119936

fbshipit-source-id: cc276dcbd1d55585d8c108b76703aa260c9c9a09

android/build.gradle

@@ -20,7 +20,7 @@ android {
         buildConfigField "boolean", "IS_INTERNAL_BUILD", 'true'
 
         ndk {
-            abiFilters 'x86_64', 'armeabi-v7a', 'arm64-v8a'
+            abiFilters 'x86', 'x86_64', 'armeabi-v7a', 'arm64-v8a'
         }
 
         externalNativeBuild {