Bump the version number for support lib in master

Moving to 25.1.0-SNAPSHOT since 25.0.0 is about to get released.

Test: no testing
Change-Id: I35c3467aec6d2176c2bf80fe9430d4f71ae55e94
diff --git a/build.gradle b/build.gradle
index b0edbd1..15f52bf 100644
--- a/build.gradle
+++ b/build.gradle
@@ -31,8 +31,8 @@
     doclava project(':doclava')
 }
 
-ext.supportVersion = '25.0.0'
-ext.extraVersion = 39
+ext.supportVersion = '25.1.0-SNAPSHOT'
+ext.extraVersion = 40
 ext.supportRepoOut = ''
 ext.buildToolsVersion = '23.0.2'
 ext.buildNumber = Integer.toString(ext.extraVersion)