Add additional build variable checks to Android.mk files

This was causing the mm command to fail when it was run from
bootable/recovery and no crypto features had been specified in
a device's configuration files

Change-Id: Iddbeea5349bbf75cddb0250cd71821dfe3b7b9d8
diff --git a/crypto/ics/Android.mk b/crypto/ics/Android.mk
index 4529ae5..fb8449d 100644
--- a/crypto/ics/Android.mk
+++ b/crypto/ics/Android.mk
@@ -1,5 +1,5 @@
 LOCAL_PATH := $(call my-dir)
-
+ifeq ($(TW_INCLUDE_CRYPTO), true)
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libcryptfsics
@@ -23,3 +23,4 @@
 LOCAL_SHARED_LIBRARIES += libc liblog libcutils libcrypto
 
 include $(BUILD_SHARED_LIBRARY)
+endif