SDK repo: use a template for samples/source.properties.

Use a template for samples/source.properties so that it automatically
picks up the current platform API level.

Also merges 52feec594a769653625f6089cfcd5398332922ea
("Update rev numbers of SDK packages.")

Change-Id: I89574842d2b0290cc6cf454f82a3721644cae0f0
diff --git a/sdk/support_source.properties b/sdk/support_source.properties
index 85af1a7..855afb3 100644
--- a/sdk/support_source.properties
+++ b/sdk/support_source.properties
@@ -1,5 +1,5 @@
 Pkg.UserSrc=false
-Pkg.Revision=6
+Pkg.Revision=8
 Extra.Vendor=android
 Extra.Path=support
 Extra.OldPaths=compatibility