Remove PadToPowerOf2 function

[dmanc]

Why are these changes needed?

Blob does not need to be padded to a power of 2, just need to ensure the chunk length is a power of 2.

Checks

• I've made sure the lint is passing in this PR.
• I've made sure the tests are passing. Note that there might be a few flaky tests, in that case, please comment that they are not relevant.
• I've checked the new test coverage and the coverage percentage didn't drop.
• Testing Strategy
  • Unit tests
  • Integration tests
  • This PR is not tested :(