pdl: Generate additional canonical test vectors

- Add tests with min and max scalar values
- Add tests for array with a size field and
  dynamically sized elements
  (real life example TLV buffers)
- Fix python generation bug with said arrays

Test: atest --host pdl_python_generator_test
(cherry picked from https://android-review.googlesource.com/q/commit:9f4ada8165aa02b0fde1b2cabc49f3a93b2814dc)
Merged-In: Iad255cc452399967e24e212a82aff747fca3b37e
Change-Id: Iad255cc452399967e24e212a82aff747fca3b37e