PLATFORM_PREVIEW_SDK_VERSION should be 2 for the next Preview/Beta Release of OC

Test: lunch marlin-userdebug && m -j40
Change-Id: I1654ab2b63ebddc79fd41f3c9d3d9e3902f03172
Fixes: 36512249
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 03629b2..2442acf 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -167,7 +167,7 @@
     # assuming the device can only support APIs as of the previous official
     # public release.
     # This value will always be 0 for release builds.
-    PLATFORM_PREVIEW_SDK_VERSION := 1
+    PLATFORM_PREVIEW_SDK_VERSION := 2
   endif
 endif