Add the VK_COMMAND_POOL_CREATE_TRANSIENT_BIT flag when creating the
PersistentCommandPool since the command buffers are only used once and
then reset. Update the tracking bugs.

Bug: b/166641492
Bug: b/166793850
Change-Id: I5827b5df7dd150756325421fc6ff0283bbd8b8e1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2381943Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: back sept 10 - Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Commit-Queue: Tobin Ehlis <tobine@google.com>