Fix PriorityHandlerTest and restore Instant import in DmfsTaskProcessor

Author: sunkup

lib/src/main/kotlin/at/bitfire/synctools/mapping/tasks/DmfsTaskProcessor.kt

@@ -42,6 +42,7 @@ import org.dmfs.tasks.contract.TaskContract.Property.Comment
 import org.dmfs.tasks.contract.TaskContract.Property.Relation
 import org.dmfs.tasks.contract.TaskContract.Tasks
 import java.net.URISyntaxException
+import java.time.Instant
 import java.time.temporal.Temporal
 import java.util.logging.Level
 import java.util.logging.Logger

lib/src/test/kotlin/at/bitfire/synctools/mapping/tasks/handler/PriorityHandlerTest.kt

@@ -11,7 +11,6 @@ import androidx.core.content.contentValuesOf
 import at.bitfire.ical4android.Task
 import org.dmfs.tasks.contract.TaskContract.Tasks
 import org.junit.Assert.assertEquals
-import org.junit.Assert.assertNull
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
@@ -22,10 +21,10 @@ class PriorityHandlerTest {
     private val handler = PriorityHandler()
 
     @Test
-    fun `No PRIORITY`() {
+    fun `No PRIORITY leaves priority at default (0)`() {
         val task = Task()
         handler.process(ContentValues(), task)
-        assertNull(task.priority)
+        assertEquals(0, task.priority)
     }
 
     @Test