Fix layout file lb_row_header.xml
Fix layout file lb_row_header.xml

android:LinearLayout is not recoginzied by Robolectric.

Bug: 35329815
Test: leanback tests
Change-Id: I7af4e4816fff2529e10dd52698e0206e11176b98

aosp-mirror/platform_frameworks_support,AndroidX/androidx,androidx/androidx,AndroidX/androidx,aosp-mirror/platform_frameworks_support,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,aosp-mirror/platform_frameworks_support,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,aosp-mirror/platform_frameworks_support,androidx/androidx,AndroidX/androidx,aosp-mirror/platform_frameworks_support,androidx/androidx,androidx/androidx,androidx/androidx