Switch the required host Java environment to 1.6.

The path to the Java toolchain is now explicitly
specified so no manual configuration should be
required.

Change-Id: I84abc122c557372e77e4579e9a9efe56af2b412c
diff --git a/core/main.mk b/core/main.mk
index 1545670..c9f5b5f 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -102,43 +102,38 @@
 endif
 
 
-# The windows build server currently uses 1.6.  This will be fixed.
-ifneq ($(HOST_OS),windows)
-
 # Check for the correct version of java
-java_version := $(shell java -version 2>&1 | head -n 1 | grep '[ "]1\.5[\. "$$]')
+java_version := $(shell java -version 2>&1 | head -n 1 | grep '[ "]1\.6[\. "$$]')
 ifeq ($(strip $(java_version)),)
 $(info ************************************************************)
 $(info You are attempting to build with the incorrect version)
 $(info of java.)
 $(info $(space))
 $(info Your version is: $(shell java -version 2>&1 | head -n 1).)
-$(info The correct version is: 1.5.)
+$(info The correct version is: 1.6.)
 $(info $(space))
 $(info Please follow the machine setup instructions at)
 $(info $(space)$(space)$(space)$(space)http://source.android.com/download)
 $(info ************************************************************)
-#$(error stop)
+$(error stop)
 endif
 
 # Check for the correct version of javac
-javac_version := $(shell javac -version 2>&1 | head -n 1 | grep '[ "]1\.5[\. "$$]')
+javac_version := $(shell javac -version 2>&1 | head -n 1 | grep '[ "]1\.6[\. "$$]')
 ifeq ($(strip $(javac_version)),)
 $(info ************************************************************)
 $(info You are attempting to build with the incorrect version)
 $(info of javac.)
 $(info $(space))
 $(info Your version is: $(shell javac -version 2>&1 | head -n 1).)
-$(info The correct version is: 1.5.)
+$(info The correct version is: 1.6.)
 $(info $(space))
 $(info Please follow the machine setup instructions at)
 $(info $(space)$(space)$(space)$(space)http://source.android.com/download)
 $(info ************************************************************)
-#$(error stop)
+$(error stop)
 endif
 
-endif # windows
-
 $(shell echo 'VERSIONS_CHECKED := $(VERSION_CHECK_SEQUENCE_NUMBER)' \
         > $(OUT_DIR)/versions_checked.mk)
 endif