Add OWNERS files to keymaster resources

This patch adds swillden@ and jdanis@ as owners of keymaster/3.0/vts
and keymaster/3.0/default.

Test: No code changed
Change-Id: I04bc0f741e8fafd53aee7c9dd62954548b81263d
diff --git a/keymaster/3.0/default/OWNERS b/keymaster/3.0/default/OWNERS
new file mode 100644
index 0000000..335660d
--- /dev/null
+++ b/keymaster/3.0/default/OWNERS
@@ -0,0 +1,2 @@
+jdanis@google.com
+swillden@google.com