Implement osu!mania-specific health bar display

osu.Game.Rulesets.Catch/Skinning/Legacy/CatchLegacySkinTransformer.cs

@@ -60,6 +60,7 @@ public CatchLegacySkinTransformer(ISkin skin)
                                 Children = new Drawable[]
                                 {
                                     new LegacyKeyCounterDisplay(),
+                                    new LegacyHealthDisplay(),
                                 }
                             };
                     }

osu.Game.Rulesets.Mania/Skinning/Legacy/ManiaLegacySkinTransformer.cs

@@ -9,13 +9,15 @@
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Objects.Legacy;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Skinning;
+using osuTK;
 
 namespace osu.Game.Rulesets.Mania.Skinning.Legacy
 {
@@ -106,6 +108,20 @@ public override Drawable GetDrawableComponent(ISkinComponentLookup lookup)
                             {
                                 new LegacyManiaComboCounter(),
                             };
+
+                        case GlobalSkinnableContainers.Playfield:
+                            return new Container
+                            {
+                                RelativeSizeAxes = Axes.Both,
+                                Child = new LegacyHealthDisplay
+                                {
+                                    Rotation = -90f,
+                                    Anchor = Anchor.BottomRight,
+                                    Origin = Anchor.TopLeft,
+                                    X = 1,
+                                    Scale = new Vector2(0.7f),
+                                },
+                            };
                     }
 
                     return null;

osu.Game.Rulesets.Osu/Skinning/Legacy/OsuLegacySkinTransformer.cs

@@ -83,6 +83,7 @@ public OsuLegacySkinTransformer(ISkin skin)
                                 {
                                     new LegacyDefaultComboCounter(),
                                     new LegacyKeyCounterDisplay(),
+                                    new LegacyHealthDisplay(),
                                 }
                             };
                     }