CtsNativeHardwareTestCases: use compute shader to write SSBO

Shader storage buffer object (SSBO) support in vertex shader is optional
according to the OpenGL ES 3.1 specification. Modify the test to use
compute shader writes to SSBOs to test blob buffers.

Bug: 115557786
Test: Passes on Pixel XL.
Change-Id: I2b4be377a2c009ae38d23b03e750bb0d01c598b2
1 file changed