Please do not paste build logs directly into the forum, they are extremely difficult to read there and make it very difficult to help. Attach them as text files to your post.
Looks to me like this is the error message:
Unknown source file : .../cordova_project/platforms/android/build/intermediates/assets/armv7/release/www/images/ejwfwqskwyamanc7eactwh_rzyzyzwu2eu0zyzuer7thuqnarplea7zizx6an8ei16mpcw0n9mdrzcukk5f0sl0ww6cx5j8fa5wdnqezycqfkbiurceac5_sgrfr5aq7ldvvzutcrr-sheet0.png: error: Invalid filename. Unable to add.
But I have no idea what that image file is (named "ejwfwqskwyamanc7eactwh...many more letters...dvvzutcrr-sheet0.png") or where it came from. Perhaps the very long name is a problem... It's located in your www/images folder in your project.
p.s. Note that the build system is being retired at the end of June, I recommend you learn how to build with PhoneGap Build or Cordova CLI. See the instructions in the docs.