Add applymapping app to opensource-apps dumps

Contents of README.google:

Name: ApplyMapping test jar input to proguard/r8
URL: https://github.com/mkj-gram/applymapping.git
Version: NA
Revision: e3ae14b8c16fa4718e5dea8f7ad00937701b3c48
Date: March 12 2019
License: 3 clause BSD licence

Bug: 152155164
Change-Id: I9cd9e9208b0e5e8d1193fe61f462dcbe703d475d
diff --git a/third_party/opensource-apps/applymapping.tar.gz.sha1 b/third_party/opensource-apps/applymapping.tar.gz.sha1
new file mode 100644
index 0000000..c71bb17
--- /dev/null
+++ b/third_party/opensource-apps/applymapping.tar.gz.sha1
@@ -0,0 +1 @@
+5f6f7b7060e6c416dad629dd62f99b7b01540f1c
\ No newline at end of file