Share Vulkan resources between RenderThread and HardwareBitmapUploader

The VkInstance and VkDevice are constructs that can be shared between
threads and avoid the extra driver allocations associated with them.

This CL also fixes a bug where Vulkan uploads were occuring on the
thread that invoked the upload and not occuring on the upload thread.

Bug: b/162628999
Test: atest CtsUiRenderingTestCases
Change-Id: I0289938333e2c3dafcc2ce18e72dca3acf4d5b79