Build bouncycastle for default java version

Due to limitations with jarjar the bouncycastle target was built for
java 1.7. Now that it no longer uses jarjar that restriction is no
longer necessary.

Bug: 117818301
Test: make checkbuild
Change-Id: I3587fa75c2a47bdfcf528d04a7cd32a46e1d63af
diff --git a/Android.bp b/Android.bp
index 44985b2..7d37383 100644
--- a/Android.bp
+++ b/Android.bp
@@ -80,7 +80,6 @@
         "core-all",
     ],
     system_modules: "core-all-system-modules",
-    java_version: "1.7",
 }
 
 // A guaranteed unstripped version of bouncycastle.