Add compose preview for launcher icons (mainly for tests)

app/build.gradle.kts

@@ -229,4 +229,6 @@ dependencies {
     testImplementation(libs.test.truth)
     testImplementation(libs.test.turbine)
     testImplementation(projects.libraries.matrix.test)
+
+    ksp(libs.showkase.processor)
 }

app/src/main/kotlin/io/element/android/x/icon/IconPreview.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.x.icon
+
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.tooling.preview.Preview
+import io.element.android.x.R
+
+@Preview
+@Composable
+fun IconPreview(
+    modifier: Modifier = Modifier,
+) {
+    Box {
+        Image(painter = painterResource(id = R.mipmap.ic_launcher_background), contentDescription = null)
+        Image(painter = painterResource(id = R.mipmap.ic_launcher_foreground), contentDescription = null)
+    }
+}
+
+@Preview
+@Composable
+fun RoundIconPreview(
+    modifier: Modifier = Modifier,
+) {
+    Box(modifier = modifier.clip(shape = CircleShape)) {
+        Image(painter = painterResource(id = R.mipmap.ic_launcher_background), contentDescription = null)
+        Image(painter = painterResource(id = R.mipmap.ic_launcher_foreground), contentDescription = null)
+    }
+}