tunnel: the external API does not expose java9

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

tunnel/build.gradle

@@ -24,8 +24,8 @@ android {
 }
 
 dependencies {
-    api "net.sourceforge.streamsupport:android-retrofuture:$streamsupportVersion"
-    api "net.sourceforge.streamsupport:android-retrostreams:$streamsupportVersion"
+    implementation "net.sourceforge.streamsupport:android-retrofuture:$streamsupportVersion"
+    implementation "net.sourceforge.streamsupport:android-retrostreams:$streamsupportVersion"
     implementation "androidx.annotation:annotation:$annotationsVersion"
     implementation "androidx.collection:collection:$collectionVersion"
     implementation "com.google.code.findbugs:jsr305:$jsr305Version"

ui/build.gradle

@@ -83,6 +83,8 @@ dependencies {
     implementation "com.google.android.material:material:$materialComponentsVersion"
     implementation "com.journeyapps:zxing-android-embedded:$zxingEmbeddedVersion"
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion"
+    implementation "net.sourceforge.streamsupport:android-retrofuture:$streamsupportVersion"
+    implementation "net.sourceforge.streamsupport:android-retrostreams:$streamsupportVersion"
 }
 
 tasks.withType(JavaCompile) {