Fix embedded build

1) Disable dexpreopt if DALVIK_VM_LIB isn't set up by the product.
2) DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES is moved to config.mk,
for it's only decided by target arch.
3) Move Java module input from embedded.mk to base.mk.

Change-Id: Ife70b0cd8cee2e5c92f356c808affa56f494b49a
diff --git a/target/product/base.mk b/target/product/base.mk
index 68e3ff3..8aa3bc0 100644
--- a/target/product/base.mk
+++ b/target/product/base.mk
@@ -34,6 +34,7 @@
     framework2 \
     fsck_msdos \
     ime \
+    input \
     javax.obex \
     libandroid \
     libandroid_runtime \