docs: update template files with those from the templates-ds directory

Change-Id: I47b07b17ea79d0b00300492ba7854e37f1ab00d0
diff --git a/tools/droiddoc/templates-sdk/timestamp.cs b/tools/droiddoc/templates-sdk/timestamp.cs
new file mode 100644
index 0000000..4bf502a
--- /dev/null
+++ b/tools/droiddoc/templates-sdk/timestamp.cs
@@ -0,0 +1 @@
+var BUILD_TIMESTAMP = "<?cs var:page.now ?>";