Revert "Create StarboardBridge native class with jni_generator (#4545)"

This reverts commit 4580609.

cobalt/android/BUILD.gn

@@ -32,21 +32,13 @@ jinja_template("cobalt_manifest") {
   variables = [ "manifest_package=dev.cobalt.coat" ]
 }
 
-generate_jni("jni_headers") {
-  sources = [ "apk/app/src/main/java/dev/cobalt/coat/StarboardBridge.java" ]
-}
-
 # TODO(cobalt): Re-enable or remove disabled java files.
 android_library("cobalt_apk_java") {
   testonly = true
   resources_package = "dev.cobalt.coat"
-  annotation_processor_deps = [ "//base/android/jni_generator:jni_processor" ]
-
   deps = [
     ":cobalt_java_resources",
-    ":jni_headers",
     "//base:base_java",
-    "//base:jni_java",
     "//base:process_launcher_java",
     "//build/android:build_java",
     "//components/embedder_support/android:view_java",
@@ -65,7 +57,6 @@ android_library("cobalt_apk_java") {
     "//ui/android:ui_no_recycler_view_java",
     "//url:gurl_java",
   ]
-
   sources = [
     "apk/app/src/app/java/dev/cobalt/app/CobaltApplication.java",
     "apk/app/src/app/java/dev/cobalt/app/MainActivity.java",