[WebLayer Shell] Make URL TextView clickable again.

I had removed the clicklistener on the TextView for the demo app
here:
https://chromium-review.googlesource.com/c/chromium/src/+/2362817

since I was setting it on the parent view. Turns out, to make the child
TextView clicks go up to the parent, I'll need to mark it non-clickable in the
layout xml, which we don't want to do for production.

Adding the click listener explicitly on the TextView fixes this.

Change-Id: I7feaf35a436abb4ca4313f94b12e448c74f58562
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2366900Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800109}

weblayer/shell/android/shell_apk/src/org/chromium/weblayer/shell/WebLayerShellActivity.java

@@ -382,6 +382,11 @@ public class WebLayerShellActivity extends FragmentActivity {
                         .setTextSizeSP(DEFAULT_TEXT_SIZE)
                         .setTextColor(android.R.color.black)
                         .setIconColor(android.R.color.black)
+                        .setTextClickListener(v -> {
+                            mEditUrlView.setText("");
+                            mUrlViewContainer.setDisplayedChild(EDITABLE_URL_TEXT_VIEW);
+                            mEditUrlView.requestFocus();
+                        })
                         .setTextLongClickListener(v -> {
                             ClipboardManager clipboard =
                                     (ClipboardManager) v.getContext().getSystemService(