Some features were used but not enabled.  There is no validation error
for this.  This change enables the following features:

- shaderStorageBufferArrayDynamicIndexing: used by atomic counter
  emulation.
- shaderSampledImageArrayDynamicIndexing: used by sampler array of array
  emulation, as well EXT_gpu_shader5.
- shaderUniformBufferArrayDynamicIndexing: used by EXT_gpu_shader5.

Bug: angleproject:4071
Change-Id: I582750d1552055deeec50485e6511788b98490c2
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2032144Reviewed-by: Tobin Ehlis <tobine@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>