gradle: desugar retrofuture and remove old deps

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

tunnel/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -32,8 +32,6 @@ import java.util.Objects;
 import java.util.Set;
 
 import androidx.annotation.Nullable;
-import java9.util.stream.Collectors;
-import java9.util.stream.Stream;
 
 /**
  * WireGuard backend that uses {@code wg-quick} to implement tunnel configuration.
@@ -67,7 +65,7 @@ public final class WgQuickBackend implements Backend {
             return Collections.emptySet();
         }
         // wg puts all interface names on the same line. Split them into separate elements.
-        return Stream.of(output.get(0).split(" ")).collect(Collectors.toUnmodifiableSet());
+        return Set.of(output.get(0).split(" "));
     }
 
     @Override

tunnel/src/main/java/com/wireguard/config/Attribute.java

@@ -8,11 +8,10 @@ package com.wireguard.config;
 import com.wireguard.util.NonNullForAll;
 
 import java.util.Iterator;
+import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import java9.util.Optional;
-
 @NonNullForAll
 public final class Attribute {
     private static final Pattern LINE_PATTERN = Pattern.compile("(\\w+)\\s*=\\s*([^\\s#][^#]*)");

tunnel/src/main/java/com/wireguard/config/InetEndpoint.java

@@ -7,18 +7,17 @@ package com.wireguard.config;
 
 import com.wireguard.util.NonNullForAll;
 
-import org.threeten.bp.Duration;
-import org.threeten.bp.Instant;
-
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.UnknownHostException;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Optional;
 import java.util.regex.Pattern;
 
 import androidx.annotation.Nullable;
-import java9.util.Optional;
 
 
 /**

tunnel/src/main/java/com/wireguard/config/Interface.java

@@ -20,13 +20,11 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import androidx.annotation.Nullable;
-import java9.util.Lists;
-import java9.util.Optional;
-import java9.util.stream.Collectors;
-import java9.util.stream.StreamSupport;
 
 /**
  * Represents the configuration for a WireGuard interface (an [Interface] block). Interfaces must
@@ -223,9 +221,7 @@ public final class Interface {
         if (!addresses.isEmpty())
             sb.append("Address = ").append(Attribute.join(addresses)).append('\n');
         if (!dnsServers.isEmpty()) {
-            final List<String> dnsServerStrings = StreamSupport.stream(dnsServers)
-                    .map(InetAddress::getHostAddress)
-                    .collect(Collectors.toUnmodifiableList());
+            final List<String> dnsServerStrings = dnsServers.stream().map(InetAddress::getHostAddress).collect(Collectors.toList());
             sb.append("DNS = ").append(Attribute.join(dnsServerStrings)).append('\n');
         }
         if (!excludedApplications.isEmpty())
@@ -339,11 +335,11 @@ public final class Interface {
         }
 
         public Builder parseExcludedApplications(final CharSequence apps) {
-            return excludeApplications(Lists.of(Attribute.split(apps)));
+            return excludeApplications(List.of(Attribute.split(apps)));
         }
 
         public Builder parseIncludedApplications(final CharSequence apps) {
-            return includeApplications(Lists.of(Attribute.split(apps)));
+            return includeApplications(List.of(Attribute.split(apps)));
         }
 
         public Builder parseListenPort(final String listenPort) throws BadConfigException {

tunnel/src/main/java/com/wireguard/config/Peer.java

@@ -17,10 +17,10 @@ import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Locale;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 
 import androidx.annotation.Nullable;
-import java9.util.Optional;
 
 /**
  * Represents the configuration for a WireGuard peer (a [Peer] block). Peers must have a public key,