Use actual numbers in version numbers.

This string is used in the browser user agent, and some
sites get confused when this isn't a dotted-number version
number into thinking that they should serve stripped down HTML.
This clears the confusion.

Change-Id: I6c959ff17c540a1f3808f19238b9eb93ba170d2e
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 2f57cf7..b38efe3 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -41,7 +41,7 @@
   # which is the version that we reveal to the end user.
   # Update this value when the platform version changes (rather
   # than overriding it somewhere else).  Can be an arbitrary string.
-  PLATFORM_VERSION := AOSP
+  PLATFORM_VERSION := 3.1.4.1.5.9.2.6.5
 endif
 
 ifeq "" "$(PLATFORM_SDK_VERSION)"