Changes default uniform block layout generation to only remove the first
array subscript, which causes arrays of arrays to be recognized
correctly.

Bug: angleproject:3604
Test: ./angle_deqp_gles31_no_gtest --deqp-egl-display-type=angle-vulkan -n 'dEQP-GLES31.functional.shaders.arrays*'
Test: ./angle_deqp_gles31_no_gtest --deqp-egl-display-type=angle-vulkan -n 'dEQP-GLES31.functional.program_interface_query.*array*array*'
Change-Id: Ifacc665cae87c651253e5cb8d929178d7fc92817
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1724906Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: James Dong <dongja@google.com>