Fixed Android.common.mk #define setting for small art

We were seeing things compile when they shouldn't have. This fixes it.  Plus added
a bit more documentation to options, set default values for the two small art related
thresholds to zero.

Change-Id: Id5db11962f3e30d8d4ee6b85d4cf7d6e66323adb
diff --git a/src/compiler/driver/compiler_driver.cc b/src/compiler/driver/compiler_driver.cc
index 67a55f6..5ddd0a6 100644
--- a/src/compiler/driver/compiler_driver.cc
+++ b/src/compiler/driver/compiler_driver.cc
@@ -1649,11 +1649,12 @@
     } else if (code_item->insns_size_in_code_units_ < Runtime::Current()->GetSmallModeMethodDexSizeLimit()) {
     // Do compile small methods.
       dont_compile = false;
+      LOG(INFO) << "Compiling a small method: " << PrettyMethod(method_idx, dex_file);
     }
 
     if (!dont_compile) {
       compiled_method = (*compiler_)(*this, code_item, access_flags, invoke_type, class_def_idx,
-          method_idx, class_loader, dex_file);
+                                     method_idx, class_loader, dex_file);
       CHECK(compiled_method != NULL) << PrettyMethod(method_idx, dex_file);
     }
   }