Add shared project settings to git.

Adding copyright configuration
 > It will automatically add correct copyright to new files.
Adding code style
 > It will automatically format Java code correctly based on Android style.
Adding VCS configuration
 > It will not prompt users to add git repositories, it will just be set
   by default.

These files are safe to check in according to Intellij support:
https://intellij-support.jetbrains.com/hc/en-us/articles/206544839

Test: None
Change-Id: I6fd3a6f93d35287f9a057417dec5be7bfd8e5702
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..b24c09a
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/../../external/doclava" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/../../external/jdiff" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file