Reland "Set StylusHandwritingImeCallback when the web contents is updated"

StylusHandwritingImeCallback is set when web contents are updated, this allowed Direct writing service to request for edit bounds when spen hover over editable fields and blocks navigation icons (back/home/menu) to allow direct writing.

Direct writing service expects onlyRectChanged key along with bundle when only edit field bounds have changed to avoid blocking navigation icons. Issue was happening because this key was not passed with bundle.

Added onlyRectChanged key to bundle when onBoundedEditTextChanged API is called.

This is a reland of commit 2b1ed86013047fdae98768896e3954e832c19327

Original change's description:
> Set StylusHandwritingImeCallback when the web contents is updated
>
> The Stylus Handwriting Toolbar in Chromium was unresponsive when an
> input field was focused without performing any direct writing actions.
> This issue occurred due to the StylusHandwritingImeCallback being set
> only when initiating stylus writing.
>
> Set StylusHandwritingImeCallback when the web contents is updated.
> This ensures that the callback is available even when an input field
> is focused without performing direct writing action.
>
> Bug: 1455060
> Change-Id: Iba56f9d21e31372b4c378da4d2d838a0bfc231bc
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4617691
> Reviewed-by: Robert Flack <flackr@chromium.org>
> Reviewed-by: Peter Conn <peconn@chromium.org>
> Commit-Queue: Mahesh Machavolu <mahesh.ma@samsung.com>
> Reviewed-by: David Trainor <dtrainor@chromium.org>
> Reviewed-by: Mahesh Machavolu <mahesh.ma@samsung.com>
> Reviewed-by: Alex Mitra <alexmitra@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1162768}

Bug: 1455060
Change-Id: I18b5868326b5dd11fd6fbc5ec974e83d9cd3aeb1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5003916
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Mahesh Machavolu <mahesh.ma@samsung.com>
Reviewed-by: Peter Conn <peconn@chromium.org>
Commit-Queue: Mahesh Machavolu <mahesh.ma@samsung.com>
Reviewed-by: Alex Mitra <alexmitra@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1222764}

• components/stylus_handwriting/android/java/src/org/chromium/components/stylus_handwriting/AndroidStylusWritingHandler.java[diff]
• components/stylus_handwriting/android/java/src/org/chromium/components/stylus_handwriting/DirectWritingBundleUtil.java[diff]
• components/stylus_handwriting/android/java/src/org/chromium/components/stylus_handwriting/DirectWritingServiceBinder.java[diff]
• components/stylus_handwriting/android/java/src/org/chromium/components/stylus_handwriting/DirectWritingTrigger.java[diff]
• components/stylus_handwriting/android/junit/src/org/chromium/components/stylus_handwriting/AndroidStylusWritingHandlerTest.java[diff]
• components/stylus_handwriting/android/junit/src/org/chromium/components/stylus_handwriting/DirectWritingTriggerTest.java[diff]
• content/public/android/java/src/org/chromium/content/browser/input/ImeAdapterImpl.java[diff]
• content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java[diff]
• content/public/android/java/src/org/chromium/content_public/browser/StylusWritingHandler.java[diff]
• content/public/android/java/src/org/chromium/content_public/browser/WebContents.java[diff]
• content/public/test/android/javatests/src/org/chromium/content_public/browser/test/mock/MockWebContents.java[diff]