Vulkan: Bug fix in texture respecification code When a target texture is created from an EGL image, respecification of the texture needs to take into account the fact that it din't own the ImageHelper. Refactor copy and stage code to account for this possibility as well. Bug: angleproject:3756 Bug: angleproject:5281 Test: ImageTest.Source2DTarget2DTargetTextureRespecify* Change-Id: I2e3bd5d1d64e85da521a841423cfe24673efe88f Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2524703 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>