Adjust the background text image width to reduce its size

We can adjust the image width with respect to the maximum width of the
wrapped text. This will remove some black margins and reduce the final
size of the images, especially for those with short strings, e.g.
"recovery_error".

Also, add an option to centrally align the text; and fix a boundary
check in the recovery resource test.

Bug: 74397117
Test: Generate and check the image
Change-Id: Ib6cf61a9c99c4aeede16751dc0adfa23ce3f5424