Reland "Enable vertex ID support on Metal"

This reverts commit 70698046219f0100b26e9c73628c683ffea2b9eb.

Bug: skia:12010
Change-Id: Ifbb17904e0157020481b3f98aaefb98df5150afb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/429298
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/mtl/GrMtlCaps.mm b/src/gpu/mtl/GrMtlCaps.mm
index fd472cc..1581751 100644
--- a/src/gpu/mtl/GrMtlCaps.mm
+++ b/src/gpu/mtl/GrMtlCaps.mm
@@ -475,7 +475,7 @@
 
     shaderCaps->fIntegerSupport = true;
     shaderCaps->fNonsquareMatrixSupport = true;
-    shaderCaps->fVertexIDSupport = false;
+    shaderCaps->fVertexIDSupport = true;
     shaderCaps->fInfinitySupport = true;
 
     // Metal uses IEEE float and half floats so assuming those values here.