Allow manually specifying translations for modules

Parse the comment block above each module or assignment looking
for directives in the form:
Android.mk:<directive>
If a block delimited by start and end directives is found, use it
as the Android.mk translation instead of trying to automatically
translate.  If an ignore directive is found, ignore the module
completely.

Change-Id: I34fe392899ed27ce3f640a2a71fbbaaedea67169

androidbp/cmd/androidbp_test.go

@@ -117,6 +117,20 @@ var moduleTestCases = []struct {
 			    LOCAL_MODULE := test
 			    include $(BUILD_HOST_STATIC_LIBRARY)`,
 	},
+	// Manual translation
+	{
+		blueprint: `/* Android.mk:start
+					# Manual translation
+					Android.mk:end */
+					cc_library { name: "test", host_supported: true, }`,
+		androidmk: `# Manual translation`,
+	},
+	// Ignored translation
+	{
+		blueprint: `/* Android.mk:ignore */
+					cc_library { name: "test", host_supported: true, }`,
+		androidmk: ``,
+	},
 }
 
 func TestModules(t *testing.T) {