Disable openssl for folly libevent builds too

Summary:
This has been tripping up the release builds, luckily caught by
Circle: https://circleci.com/gh/facebook/flipper/1480

Reviewed By: jknoxville

Differential Revision: D17282130

fbshipit-source-id: a17adb18bc75e4fa5d645a062343622167785fa6

android/third-party/overrides/Folly/build.gradle

@@ -17,7 +17,7 @@ android {
         buildConfigField "boolean", "IS_INTERNAL_BUILD", 'true'
         externalNativeBuild {
             cmake {
-                arguments '-DANDROID_TOOLCHAIN=clang', '-DANDROID_STL=c++_shared'
+                arguments '-DANDROID_TOOLCHAIN=clang', '-DANDROID_STL=c++_shared', '-DEVENT__DISABLE_OPENSSL=on'
             }
         }
     }