refactor: Deprecate custom functional interfaces

Author: valfirst

src/main/java/io/appium/java_client/functions/ActionSupplier.java

@@ -20,6 +20,12 @@
 
 import java.util.function.Supplier;
 
+/**
+ * Represents a supplier of actions.
+ *
+ * @deprecated Use {@link Supplier} instead
+ */
+@Deprecated
 @FunctionalInterface
 public interface ActionSupplier<T extends PerformsActions<?>> extends Supplier<T> {
 }

src/main/java/io/appium/java_client/functions/AppiumFunction.java

@@ -28,7 +28,9 @@
  *
  * @param <F> The input type
  * @param <T> The return type
+ * @deprecated Use {@link java.util.function.Function} instead
  */
+@Deprecated
 @FunctionalInterface
 public interface AppiumFunction<F, T>  extends Function<F, T>, java.util.function.Function<F, T> {
 

src/main/java/io/appium/java_client/functions/ExpectedCondition.java

@@ -23,7 +23,9 @@
  * with {@link java.util.function.Function}.
  *
  * @param <T> The return type
+ * @deprecated Use {@link org.openqa.selenium.support.ui.ExpectedCondition} instead
  */
+@Deprecated
 @FunctionalInterface
 public interface ExpectedCondition<T> extends org.openqa.selenium.support.ui.ExpectedCondition<T>,
         AppiumFunction<WebDriver, T> {