Reproduction steps:(Errors in the Edit)
1) Open users attached project and build for Android platform.
-You should see errors pop up in the console.
2) Shorten AssetBundle name in the StreamingAssets and Build again.
-Build should be successful.

Expected result: Build should go through fine without any errors - as does PC build for example.
Actual result: There are two errors thrown into a console and build process is terminated. (errors differ in 5.3 and 5.4)

Unity could warn users for this bug before trying to build the APK, or, detect when the error happens ("Invalid filename") and mention the known issue.

Note: AssetBundle name consists of around 100 characters.

Workaround: Since names that use over 100 characters are unnecessary and irrational, you could always use shorter ones.

Reproduced with: 5.4.0b9 , 5.3.3p3 , 5.2.4f1