[SPARK-32476][CORE] ResourceAllocator.availableAddrs should be determ…

…inistic

### What changes were proposed in this pull request?

This PR aims to make `ResourceAllocator.availableAddrs` deterministic.

### Why are the changes needed?

Currently, this function returns indeterministically due to the underlying `HashMap`. So, the test case itself is creating a list `[0, 1, 2]` initially, but ends up with comparing `[2, 1, 0]`.

Not only this happens in the 3.0.0, but also this causes UT failures on Scala 2.13 environment.

### Does this PR introduce _any_ user-facing change?

Yes, but this fixes the in-deterministic behavior.

### How was this patch tested?

- Scala 2.12: This should pass the UT with the modified test case.
- Scala 2.13: This can be tested like the following (at least `JsonProtocolSuite`)

```
$ dev/change-scala-version.sh 2.13
$ build/mvn test -pl core --am -Pscala-2.13 -Dtest=none -DwildcardSuites=org.apache.spark.deploy.JsonProtocolSuite
```

**BEFORE**
```
*** 2 TESTS FAILED ***
```

**AFTER**
```
All tests passed.
```

Closes apache#29281 from dongjoon-hyun/SPARK-32476.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

core/src/main/scala/org/apache/spark/resource/ResourceAllocator.scala

@@ -56,7 +56,7 @@ trait ResourceAllocator {
   def availableAddrs: Seq[String] = addressAvailabilityMap
     .flatMap { case (addr, available) =>
       (0 until available).map(_ => addr)
-    }.toSeq
+    }.toSeq.sorted
 
   /**
    * Sequence of currently assigned resource addresses.
@@ -68,7 +68,7 @@ trait ResourceAllocator {
   private[spark] def assignedAddrs: Seq[String] = addressAvailabilityMap
     .flatMap { case (addr, available) =>
       (0 until slotsPerAddress - available).map(_ => addr)
-    }.toSeq
+    }.toSeq.sorted
 
   /**
    * Acquire a sequence of resource addresses (to a launched task), these addresses must be

core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala

@@ -128,8 +128,8 @@ object JsonConstants {
       |:["3","4","5"]}},"resourcesused":{"gpu":
       |{"name":"gpu","addresses":[]},"fpga":
       |{"name":"fpga","addresses":[]}},"resourcesfree":
-      |{"gpu":{"name":"gpu","addresses":["2","1","0"]},
-      |"fpga":{"name":"fpga","addresses":["5","4","3"]}},
+      |{"gpu":{"name":"gpu","addresses":["0","1","2"]},
+      |"fpga":{"name":"fpga","addresses":["3","4","5"]}},
       |"state":"ALIVE","lastheartbeat":%d}
     """.format(currTimeInMillis).stripMargin