Log the time until the Animation finishes as "Animating" (#34538)

Stacked on #34522.

<img width="1025" height="200" alt="Screenshot 2025-09-19 at 6 37 28 PM"
src="https://github.com/user-attachments/assets/f25900f6-6503-48b1-876d-bd6697a29c6f"
/>

We already cover the time between "Starting Animation" and "Remaining
Effects" as "Animating". However, if the effects are forced then we can
still be animating after that. This fills in that gap.

This also fills in the gap if another render starts before the animation
finishes on the same track. It'll mark the blank space between the
previous render finishing and the next render starting as "Animating".

This should correspond roughly to the native "Animations" track.

DiffTrain build for [b4fe1e6](b4fe1e6)

Author: sebmarkbage

compiled/facebook-www/REVISION

@@ -1 +1 @@
-b204edda3aa397243faa267512811b778542f6a5
+b4fe1e6c7eb3807afbbdad7bac4cc6bb2ad7efaf

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-b204edda3aa397243faa267512811b778542f6a5
+b4fe1e6c7eb3807afbbdad7bac4cc6bb2ad7efaf

compiled/facebook-www/React-dev.classic.js

@@ -1419,7 +1419,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-classic-b204edda-20250920";
+    exports.version = "19.2.0-www-classic-b4fe1e6c-20250920";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-dev.modern.js

@@ -1419,7 +1419,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-modern-b204edda-20250920";
+    exports.version = "19.2.0-www-modern-b4fe1e6c-20250920";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-prod.classic.js

@@ -602,4 +602,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-b204edda-20250920";
+exports.version = "19.2.0-www-classic-b4fe1e6c-20250920";

compiled/facebook-www/React-prod.modern.js

@@ -602,4 +602,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-b204edda-20250920";
+exports.version = "19.2.0-www-modern-b4fe1e6c-20250920";

compiled/facebook-www/React-profiling.classic.js

@@ -606,7 +606,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-b204edda-20250920";
+exports.version = "19.2.0-www-classic-b4fe1e6c-20250920";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-profiling.modern.js

@@ -606,7 +606,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-b204edda-20250920";
+exports.version = "19.2.0-www-modern-b4fe1e6c-20250920";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&