[SPARK-22093][TESTS] Fixes assume in UtilsSuite and HiveDDLSuite

## What changes were proposed in this pull request?

This PR proposes to remove `assume` in `Utils.resolveURIs` and replace `assume` to `assert` in `Utils.resolveURI` in the test cases in `UtilsSuite`.

It looks `Utils.resolveURIs` supports multiple but also single paths as input. So, it looks not meaningful to check if the input has `,`.

For the test for `Utils.resolveURI`, I replaced it to `assert` because it looks taking single path and in order to prevent future mistakes when adding more tests here.

For `assume` in `HiveDDLSuite`, it looks it should be `assert` to test at the last
## How was this patch tested?

Fixed unit tests.

Author: hyukjinkwon <[email protected]>

Closes #19332 from HyukjinKwon/SPARK-22093.

Author: HyukjinKwon

core/src/test/scala/org/apache/spark/util/UtilsSuite.scala

@@ -460,7 +460,7 @@ class UtilsSuite extends SparkFunSuite with ResetSystemProperties with Logging {
   test("resolveURI") {
     def assertResolves(before: String, after: String): Unit = {
       // This should test only single paths
-      assume(before.split(",").length === 1)
+      assert(before.split(",").length === 1)
       def resolve(uri: String): String = Utils.resolveURI(uri).toString
       assert(resolve(before) === after)
       assert(resolve(after) === after)
@@ -488,7 +488,6 @@ class UtilsSuite extends SparkFunSuite with ResetSystemProperties with Logging {
 
   test("resolveURIs with multiple paths") {
     def assertResolves(before: String, after: String): Unit = {
-      assume(before.split(",").length > 1)
       def resolve(uri: String): String = Utils.resolveURIs(uri)
       assert(resolve(before) === after)
       assert(resolve(after) === after)

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala

@@ -676,7 +676,7 @@ class HiveDDLSuite
       |""".stripMargin)
     val newPart = catalog.getPartition(TableIdentifier("boxes"), Map("width" -> "4"))
     assert(newPart.storage.serde == Some(expectedSerde))
-    assume(newPart.storage.properties.filterKeys(expectedSerdeProps.contains) ==
+    assert(newPart.storage.properties.filterKeys(expectedSerdeProps.contains) ==
       expectedSerdeProps)
   }