Rename jetifier property and add it to androidmk

Rename jetifier_enabled to jetifier since there are no users
yet and it is more consistent with the rest of the Soong
properties.  Also add it to androidmk translation.

Fixes: 123524520
Test: androidmk_test.go
Change-Id: Ib4c688cf3cb171a822ddf7dd49467522c4c1276c
diff --git a/java/java.go b/java/java.go
index 3eae932..1fd0a9e 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1726,7 +1726,7 @@
 	Exclude_dirs []string
 
 	// if set to true, run Jetifier against .jar file. Defaults to false.
-	Jetifier_enabled *bool
+	Jetifier *bool
 }
 
 type Import struct {
@@ -1771,7 +1771,7 @@
 	outputFile := android.PathForModuleOut(ctx, "combined", jarName)
 	TransformJarsToJar(ctx, outputFile, "for prebuilts", jars, android.OptionalPath{},
 		false, j.properties.Exclude_files, j.properties.Exclude_dirs)
-	if Bool(j.properties.Jetifier_enabled) {
+	if Bool(j.properties.Jetifier) {
 		inputFile := outputFile
 		outputFile = android.PathForModuleOut(ctx, "jetifier", jarName)
 		TransformJetifier(ctx, outputFile, inputFile)