Make title longer in ContextMenuHeaderTest for ellipsizing assertion

Sample build with failed test: https://ci.chromium.org/b/8702341957797256433
Affected test(s):
[ninja://chrome/android:chrome_public_unit_test_apk/org.chromium.chrome.browser.contextmenu.ContextMenuHeaderViewTest#testTitleAndUrlClick](https://ci.chromium.org/ui/test/chromium/ninja:%2F%2Fchrome%2Fandroid:chrome_public_unit_test_apk%2Forg.chromium.chrome.browser.contextmenu.ContextMenuHeaderViewTest%23testTitleAndUrlClick?q=VHash%3A7e26327b7b189660)

You can see in the screenshot the long title is actually not ellipsized.
This change should fix the test.

Bug: 44485377
Change-Id: Id8e83044d311b1bb8d5d7b07663dbc8db77ef611
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7000769
Commit-Queue: Jenna Himawan <jhimawan@google.com>
Reviewed-by: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/main@{#1522981}