Check for "Radeon" in renderer string.

AMD workarounds relied on the vendor string containing "AMD" or
"ATI". Some vendor strings only contain "Radeon", which lead to
workarounds not being enabled.

Bug: angleproject:5004
Change-Id: Ie32852212afd1df1f3f691c87a5459e1b53b74b6
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2385932
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -53,7 +53,8 @@ VendorID GetVendorID(const FunctionsGL *functions)
         return VENDOR_ID_NVIDIA;
     }
     else if (nativeVendorString.find("ATI") != std::string::npos ||
-             nativeVendorString.find("AMD") != std::string::npos)
+             nativeVendorString.find("AMD") != std::string::npos ||
+             nativeVendorString.find("Radeon") != std::string::npos)
     {
         return VENDOR_ID_AMD;
     }