Add ApplicationManifest (#23)

Summary:
This is used by the generateReleaseBuildConfig, which is needed when
fbjni is included as a submodule.
Pull Request resolved: facebookincubator/fbjni#23

Test Plan:
`./gradlew generateReleaseBuildConfig`
(In PyTorch) `./gradlew assembleRelease`

Reviewed By: passy

Differential Revision: D18226540

Pulled By: dreiss

fbshipit-source-id: c4ece2d1d8e7cbb095bc6991bbad53393e6f6ecb

first-party/fbjni/ApplicationManifest.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest package="com.facebook.fbjni">
+</manifest>