Switch to use commandline parser

The commandline parser adds some flexibility to the argument parsing. It
also makes the help message more descriptive.

Bug: 74397117
Test: generate a image, checks the help message
Change-Id: Ib238658a9a6fa8806f1b0dde419c8fb970e7cb37

tools/image_generator/Android.bp

@@ -17,7 +17,11 @@ java_library_host {
 
     manifest: "ImageGenerator.mf",
 
+    static_libs: [
+        "commons-cli-1.2",
+    ],
+
     srcs: [
         "ImageGenerator.java",
     ],
-}
+}