[CT] Limit bottom controls height for bottom bar

The maximum bottom bar height is 120dp. However, the bottom controls
were not limited by the bottom bar height. This could shrink the web contents height.

This CL ensures the bottom controls height is set based on the bottom
bar height instead of the child view.

(cherry picked from commit fbed4de)

Bug: 1434438
Change-Id: Ia36a8b3b222bf169ac5bda0740c735466244eeb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4606514
Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Reviewed-by: Kevin Grosu <kgrosu@google.com>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Original-Commit-Position: refs/heads/main@{#1155852}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4617149
Auto-Submit: Sinan Sahin <sinansahin@google.com>
Commit-Queue: Kevin Grosu <kgrosu@google.com>
Cr-Commit-Position: refs/branch-heads/5790@{#770}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabBottomBarDelegate.java

@@ -248,7 +248,7 @@ public int getBottomBarHeight() {
             return 0;
         }
         if (mBottomBarHeightOverride != -1) return mBottomBarHeightOverride;
-        return mBottomBarView.getChildAt(1).getHeight();
+        return mBottomBarView.getHeight();
     }
 
     /**