Fix missing case for ANGLE_depth_texture
Happens when ANGLE_depth_texure is exposed and not OES_depth_texture.
Component: AOSP
Affects:
dEQP-GLES2.functional.fbo.completeness.renderable.texture.stencil.depth_stencil_unsigned_int_24_8
dEQP-GLES2.functional.fbo.completeness.renderable.texture.depth.depth_stencil_unsigned_int_24_8
dEQP-GLES3.functional.fbo.completeness.renderable.texture.stencil.depth_stencil_unsigned_int_24_8
dEQP-GLES3.functional.fbo.completeness.renderable.texture.depth.depth_stencil_unsigned_int_24_8