[USDU-331] Samples json update (#381)

* Ignores two unstable test cases until a fix has been found

* Updates .Sample.json files and Copyright text for .cs files in Sample directory

* Updates .Sample.json for USDTimelinePlayable

* Applying code review

---------

Co-authored-by: Vicky Clark <45685026+vickycl@users.noreply.github.com>

Author: lee-aandrew

package/com.unity.formats.usd/Samples/ExportMesh/.sample.json

@@ -1,4 +1,4 @@
 {
     "displayName" : "ExportMesh",
-    "description" : "A sample showing how to record a scene to a USD file."
+    "description" : "A sample showing how GameObject can be exported as a USD file (with animation) using Unity's USD APIs directly."
 }

package/com.unity.formats.usd/Samples/HelloUsd/.sample.json

@@ -1,4 +1,4 @@
 {
     "displayName" : "HelloUsd",
-    "description" : "A sample showing how to write custom data to USDs."
+    "description" : "A sample showing how to write and read custom data to and from USDs."
 }

package/com.unity.formats.usd/Samples/ImportMaterials/.sample.json

@@ -1,4 +1,4 @@
 {
     "displayName" : "ImportMaterials",
-    "description" : "A sample showing how to import materials from a USD into Unity."
+    "description" : "A sample showing how to import materials from a USD into Unity using Unity's USD APIs directly."
 }

package/com.unity.formats.usd/Samples/ImportMesh/.sample.json

@@ -1,4 +1,4 @@
 {
     "displayName" : "ImportMesh",
-    "description" : "A sample showing how to import a scene from USD into Unity."
+    "description" : "A sample showing how to import a scene from USD into Unity using Unity's USD APIs directly."
 }

package/com.unity.formats.usd/Samples/ImportMesh/Editor/UsdImportMeshExampleEditor.cs

@@ -1,4 +1,4 @@
-// Copyright 2018 Jeremy Cowles. All rights reserved.
+// Copyright 2023 Unity Technologies. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.

package/com.unity.formats.usd/Samples/ImportProcessor/CombineMeshes.cs

@@ -1,3 +1,5 @@
+// Copyright 2023 Unity Technologies. All rights reserved.
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

package/com.unity.formats.usd/Samples/ImportProcessor/RegexImportProcessor.cs

@@ -1,3 +1,5 @@
+// Copyright 2023 Unity Technologies. All rights reserved.
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

package/com.unity.formats.usd/Samples/ImportProcessor/SetHideFlags.cs

@@ -1,3 +1,5 @@
+// Copyright 2023 Unity Technologies. All rights reserved.
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

package/com.unity.formats.usd/Samples/UsdTimelinePlayable/.sample.json

@@ -1,4 +1,4 @@
 {
     "displayName" : "UsdTimelinePlayable",
-    "description" : "A sample showing how to use the USD integration in Timeline."
+    "description" : "A sample showing how to use the USD integration with Unity's Timeline."
 }