Replace StringDecoder injection with simpler API

The initial reason for this `StringDecoder` was to make sure the AndroidX navigation route would not use incompatible chars in the resulting String.

For that, `Uri.encode(String)` was used, but this is an Android API (`android.net.Uri`).
Unit tests would fail because Uri is not mocked (since we are not using Robolectric).
Therefore, a `StringDecoder` interface was introduced with 2 implementations: `UriDecoder` and `FakeStringDecoder`, Hilt modules were added, etc.
FWIW, the naming of the API was misleading: `StringDecoder.decodeString(encodedString: String)` does not inform how encoded the input is, so `UriDecoder` could "decode" something that was not necessarily uri "encoded".

The solution to this problem was to simply use regular Java APIs:
- `URLDecoder.decode(urlEncodedTopicId, "UTF-8")`
- `URLEncoder.encode(topicId, "UTF-8")`

Author: SimonMarquis

core/common/src/main/java/com/google/samples/apps/nowinandroid/core/decoder/StringDecoder.kt

@@ -23,7 +23,6 @@ import com.google.samples.apps.nowinandroid.core.data.repository.NewsResourceQue
 import com.google.samples.apps.nowinandroid.core.data.repository.TopicsRepository
 import com.google.samples.apps.nowinandroid.core.data.repository.UserDataRepository
 import com.google.samples.apps.nowinandroid.core.data.repository.UserNewsResourceRepository
-import com.google.samples.apps.nowinandroid.core.decoder.StringDecoder
 import com.google.samples.apps.nowinandroid.core.model.data.FollowableTopic
 import com.google.samples.apps.nowinandroid.core.model.data.Topic
 import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
@@ -43,13 +42,12 @@ import javax.inject.Inject
 @HiltViewModel
 class TopicViewModel @Inject constructor(
     savedStateHandle: SavedStateHandle,
-    stringDecoder: StringDecoder,
     private val userDataRepository: UserDataRepository,
     topicsRepository: TopicsRepository,
     userNewsResourceRepository: UserNewsResourceRepository,
 ) : ViewModel() {
 
-    private val topicArgs: TopicArgs = TopicArgs(savedStateHandle, stringDecoder)
+    private val topicArgs: TopicArgs = TopicArgs(savedStateHandle)
 
     val topicId = topicArgs.topicId
 

core/common/src/main/java/com/google/samples/apps/nowinandroid/core/decoder/UriDecoder.kt

@@ -16,27 +16,27 @@
 
 package com.google.samples.apps.nowinandroid.feature.topic.navigation
 
-import android.net.Uri
 import androidx.annotation.VisibleForTesting
 import androidx.lifecycle.SavedStateHandle
 import androidx.navigation.NavController
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavType
 import androidx.navigation.compose.composable
 import androidx.navigation.navArgument
-import com.google.samples.apps.nowinandroid.core.decoder.StringDecoder
 import com.google.samples.apps.nowinandroid.feature.topic.TopicRoute
+import java.net.URLDecoder
+import java.net.URLEncoder
 
 @VisibleForTesting
 internal const val topicIdArg = "topicId"
 
 internal class TopicArgs(val topicId: String) {
-    constructor(savedStateHandle: SavedStateHandle, stringDecoder: StringDecoder) :
-        this(stringDecoder.decodeString(checkNotNull(savedStateHandle[topicIdArg])))
+    constructor(savedStateHandle: SavedStateHandle) :
+        this(URLDecoder.decode(checkNotNull(savedStateHandle[topicIdArg]), "UTF-8"))
 }
 
 fun NavController.navigateToTopic(topicId: String) {
-    val encodedId = Uri.encode(topicId)
+    val encodedId = URLEncoder.encode(topicId, "UTF-8")
     this.navigate("topic_route/$encodedId") {
         launchSingleTop = true
     }

core/common/src/main/java/com/google/samples/apps/nowinandroid/core/decoder/di/StringDecoderModule.kt

@@ -22,7 +22,6 @@ import com.google.samples.apps.nowinandroid.core.model.data.FollowableTopic
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResourceType.Video
 import com.google.samples.apps.nowinandroid.core.model.data.Topic
-import com.google.samples.apps.nowinandroid.core.testing.decoder.FakeStringDecoder
 import com.google.samples.apps.nowinandroid.core.testing.repository.TestNewsRepository
 import com.google.samples.apps.nowinandroid.core.testing.repository.TestTopicsRepository
 import com.google.samples.apps.nowinandroid.core.testing.repository.TestUserDataRepository
@@ -63,7 +62,6 @@ class TopicViewModelTest {
     fun setup() {
         viewModel = TopicViewModel(
             savedStateHandle = SavedStateHandle(mapOf(topicIdArg to testInputTopics[0].topic.id)),
-            stringDecoder = FakeStringDecoder(),
             userDataRepository = userDataRepository,
             topicsRepository = topicsRepository,
             userNewsResourceRepository = userNewsResourceRepository,