[graphite] Add Vulkan "renderpass"  tracking

Adds a boolean to ensure we're not trying to call draw commands
unless we're between beginRendering/endRendering.

Change-Id: Id6adc922c1e7e79966ab5682ac4d62fc76144866
Bug: b/285136232
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/705616
Reviewed-by: Nicolette Prevost <nicolettep@google.com>
Reviewed-by: James Godfrey-Kittle <jamesgk@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
2 files changed