[Impeller] convert aiks blur tests to new canvas.

ci/licenses_golden/excluded_files

@@ -145,6 +145,7 @@
 ../../../flutter/impeller/display_list/aiks_dl_atlas_unittests.cc
 ../../../flutter/impeller/display_list/aiks_dl_basic_unittests.cc
 ../../../flutter/impeller/display_list/aiks_dl_blend_unittests.cc
+../../../flutter/impeller/display_list/aiks_dl_blur_unittests.cc
 ../../../flutter/impeller/display_list/aiks_dl_clip_unittests.cc
 ../../../flutter/impeller/display_list/aiks_dl_gradient_unittests.cc
 ../../../flutter/impeller/display_list/aiks_dl_opacity_unittests.cc

display_list/dl_color.h

@@ -58,6 +58,12 @@ struct DlColor {
   static constexpr DlColor kCornflowerBlue()     {return DlColor(0xFF6495ED);};
   static constexpr DlColor kCrimson()            {return DlColor(0xFFFF5733);};
   static constexpr DlColor kAqua()               {return DlColor(0xFF00FFFF);};
+  static constexpr DlColor kOrange()             {return DlColor(0xFFFFA500);};
+  static constexpr DlColor kPurple()             {return DlColor(0xFF800080);};
+  static constexpr DlColor kLimeGreen()          {return DlColor(0xFF32CD32);};
+  static constexpr DlColor kGreenYellow()        {return DlColor(0xFFADFF2F);};
+  static constexpr DlColor kDarkMagenta()        {return DlColor(0xFF8B008B);};
+  static constexpr DlColor kOrangeRed()          {return DlColor(0xFFFF4500);};
   // clang-format on
 
   constexpr bool isOpaque() const { return getAlpha() == 0xFF; }