Simplify signatures of Optional extensions getOrDefault and getOrElse

Two generic types are not need to cover the same use cases.

KT-50484

libraries/stdlib/jdk8/src/kotlin/jvm/optionals/Optionals.kt

@@ -19,14 +19,14 @@ public fun <T : Any> Optional<T>.getOrNull(): T? = orElse(null)
  */
 @SinceKotlin("1.7")
 @ExperimentalStdlibApi
-public fun <R, T : R & Any> Optional<T>.getOrDefault(defaultValue: R): R = if (isPresent) get() else defaultValue
+public fun <T> Optional<out T & Any>.getOrDefault(defaultValue: T): T = if (isPresent) get() else defaultValue
 
 /**
  * Returns this [Optional]'s value if [present][Optional.isPresent], or otherwise the result of the [defaultValue] function.
  */
 @SinceKotlin("1.7")
 @ExperimentalStdlibApi
-public inline fun <R, T : R & Any> Optional<T>.getOrElse(defaultValue: () -> R): R =
+public inline fun <T> Optional<out T & Any>.getOrElse(defaultValue: () -> T): T =
     if (isPresent) get() else defaultValue()
 
 /**

libraries/stdlib/jdk8/test/jvm/optionals/OptionalsTest.kt

@@ -23,7 +23,7 @@ class OptionalsTest {
 
         // Return type can be a supertype
         assertNull(Optional.empty<String>().getOrDefault(null))
-        assertEquals(5.0, Optional.empty<Int>().getOrDefault<Number, Int>(5.0))
+        assertEquals(5.0, Optional.empty<Int>().getOrDefault(5.0))
     }
 
     @Test
@@ -33,7 +33,7 @@ class OptionalsTest {
 
         // Return type can be a supertype
         assertNull(Optional.empty<String>().getOrElse { null })
-        assertEquals(5.0, Optional.empty<Int>().getOrElse<Number, Int> { 5.0 })
+        assertEquals(5.0, Optional.empty<Int>().getOrElse { 5.0 })
     }
 
     @Test