[ios]: fix missing caps for D16_UNORM

Fixes "Assert failed in updateCaps (third_party/angle/src/libANGLE/ \
Context.cpp:4368): getClientVersion() < ES_3_0 || \
formatMaxSamples >= 4" as D16_UNORM caps were missing, which resulted
in GenerateTextureCapsMap skipping that format.

Bug: angleproject:6597, chromium:1413715
Change-Id: I031271e2db07d129e0c383107db2080794a11da1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4236537
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

scripts/code_generation_hashes/Metal_format_table.json

@@ -6,7 +6,7 @@
   "src/libANGLE/renderer/metal/gen_mtl_format_table.py":
     "28f3065f5d1bc65803b1218b706430ae",
   "src/libANGLE/renderer/metal/mtl_format_map.json":
-    "635fa5d81e340bf0d6c7cbbdd804b110",
+    "1bfe5f014cd73c83c279b5a2c78370a4",
   "src/libANGLE/renderer/metal/mtl_format_table_autogen.mm":
-    "c1dc9a979d33e5d55285504a7cef5e7f"
+    "9935924d4bb57d08e1328e26deaa2514"
 }

src/libANGLE/renderer/metal/mtl_format_map.json

@@ -707,6 +707,15 @@
             }
         },
         "caps_ios_platform": {
+            "MTLPixelFormatDepth16Unorm":{
+                "filterable": "true",
+                "writable": "false",
+                "blendable": "false",
+                "multisample": "true",
+                "resolve": "supportDepthAutoResolve",
+                "colorRenderable": "false",
+                "depthRenderable": "true"
+            },
             "MTLPixelFormatR8Unorm_sRGB":{
                 "filterable": "display->supportsAppleGPUFamily(1)",
                 "writable": "display->supportsAppleGPUFamily(2)",

src/libANGLE/renderer/metal/mtl_format_table_autogen.mm

@@ -4006,6 +4006,11 @@ void FormatTable::initNativeFormatCapsAutogen(const DisplayMtl *display)
                   /** colorRenderable*/ display->supportsAppleGPUFamily(1),
                   /** depthRenderable*/ false);
 
+    setFormatCaps(MTLPixelFormatDepth16Unorm, /** filterable*/ true, /** writable*/ false,
+                  /** blendable*/ false, /** multisample*/ true,
+                  /** resolve*/ supportDepthAutoResolve, /** colorRenderable*/ false,
+                  /** depthRenderable*/ true);
+
     setFormatCaps(MTLPixelFormatEAC_R11Snorm, /** filterable*/ display->supportsAppleGPUFamily(1),
                   /** writable*/ false, /** blendable*/ false, /** multisample*/ false,
                   /** resolve*/ false, /** colorRenderable*/ false, /** depthRenderable*/ false);