fix: changes according PR review feedback

Author: PavloNetrebchuk

core/src/main/java/org/openedx/core/utils/PreviewHelper.kt

@@ -45,14 +45,14 @@ object PreviewHelper {
         if (isOnline || isLocalFile(videoUrl)) {
             // Check cache first
             val cacheFile = getCacheFile(context, videoUrl)
-            if (cacheFile.exists()) {
+            result = if (cacheFile.exists()) {
                 try {
-                    result = BitmapFactory.decodeFile(cacheFile.absolutePath)
-                } catch (e: Exception) {
-                    e.printStackTrace()
+                    BitmapFactory.decodeFile(cacheFile.absolutePath)
+                } catch (_: Exception) {
+                    extractBitmapFromVideo(videoUrl, context)
                 }
             } else {
-                result = extractBitmapFromVideo(videoUrl, context)
+                extractBitmapFromVideo(videoUrl, context)
             }
         }
         return result

course/src/main/java/org/openedx/course/presentation/contenttab/ContentTabEmptyState.kt

@@ -23,9 +23,11 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import org.openedx.core.ui.IconText
 import org.openedx.core.ui.OpenEdXButton
+import org.openedx.core.ui.theme.OpenEdXTheme
 import org.openedx.core.ui.theme.appColors
 import org.openedx.core.ui.theme.appTypography
 import org.openedx.course.R
@@ -109,4 +111,12 @@ fun CourseContentAssignmentEmptyState(
         message = stringResource(id = org.openedx.core.R.string.core_no_assignments),
         onReturnToCourseClick = onReturnToCourseClick
     )
-} 
+}
+
+@Preview
+@Composable
+private fun CourseContentAllEmptyStatePreview() {
+    OpenEdXTheme {
+        CourseContentAllEmptyState({})
+    }
+}