[Unity][Android] Make text with settings link clickabe

Changes signin_view.xml to use TextViewWithClickableSpans for "You can
always choose what to sync in settings". This fixes confusing behavior
in accessibility mode when TextView is announced as tappable, but
doesn't do anything when tapped.

Bug: 945350
Change-Id: I5485868303751c7c531617b979532c13689bba87
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1539055
Auto-Submit: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644735}

chrome/android/java/res/layout/signin_view.xml

@@ -125,7 +125,7 @@
                 android:layout_marginStart="16dp"
                 android:layout_marginTop="16dp"
                 android:layout_marginEnd="16dp"/>
-            <TextView
+            <org.chromium.ui.widget.TextViewWithClickableSpans
                 android:id="@+id/signin_details_description"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"