Bump Build Tools version to 21.1.2 for compatibility with AS 1.1.

Change-Id: If0155aca2fce27daddfc96c95a5995fffd34f691

templates/include/common.ftl

diff --git a/templates/include/common.ftl b/templates/include/common.ftl
index b4602c6..c52550b 100644
--- a/templates/include/common.ftl
+++ b/templates/include/common.ftl
@@ -63,7 +63,7 @@
     <#assign min_sdk = "21"/>
 </#if>
 <#-- Set the global build tools version -->
-<#assign build_tools_version='"21.1.1"'/>
+<#assign build_tools_version='"21.1.2"'/>
 
 <#assign play_services_wearable_dependency="'com.google.android.gms:play-services-wearable:6.5.+'"/>