[Cronet] Add missing dep to unused cronet_jni_apk target

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Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester
Change-Id: Ib1efbbc14a982d5848ad6cfaa029be1f7f5bcfcf
Reviewed-on: https://chromium-review.googlesource.com/969149Reviewed-by: Misha Efimov <mef@chromium.org>
Commit-Queue: Paul Jensen <pauljensen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544146}

components/cronet/android/BUILD.gn

@@ -393,6 +393,7 @@ android_apk("cronet_jni_apk") {
   android_manifest = "sample/AndroidManifest.xml"
   deps = [
     ":cronet_impl_all_java",
+    "//third_party/android_tools:android_support_v7_appcompat_java",
   ]
 }