Remove detachChildren

Since there are no longer callers of detachChildren, remove code and
test that involve detachChildren

Test: Builds and remaining tests pass
Bug: 177557720
Change-Id: Id5b7120b7f2c289d4e7ffb5565b29e2be18d6587
diff --git a/cmds/surfacereplayer/proto/src/trace.proto b/cmds/surfacereplayer/proto/src/trace.proto
index c6f656b..79aab82 100644
--- a/cmds/surfacereplayer/proto/src/trace.proto
+++ b/cmds/surfacereplayer/proto/src/trace.proto
@@ -50,11 +50,10 @@
         CornerRadiusChange          corner_radius           = 16;
         ReparentChange              reparent                = 17;
         RelativeParentChange        relative_parent         = 18;
-        DetachChildrenChange        detach_children         = 19;
-        ReparentChildrenChange      reparent_children       = 20;
-        BackgroundBlurRadiusChange  background_blur_radius  = 21;
-        ShadowRadiusChange          shadow_radius           = 22;
-        BlurRegionsChange           blur_regions            = 23;
+        ReparentChildrenChange      reparent_children       = 19;
+        BackgroundBlurRadiusChange  background_blur_radius  = 20;
+        ShadowRadiusChange          shadow_radius           = 21;
+        BlurRegionsChange           blur_regions            = 22;
     }
 }
 
@@ -200,10 +199,6 @@
     required int32 z = 2;
 }
 
-message DetachChildrenChange {
-    required bool detach_children = 1;
-}
-
 message ShadowRadiusChange {
     required float radius = 1;
 }