[LL FIR] rename testdata to testData to avoid copyright generation

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/getOrBuildFir/annotations/annotationApplicationArgumentList.kt

@@ -0,0 +1,8 @@
+// LOOK_UP_FOR_ELEMENT_OF_TYPE: org.jetbrains.kotlin.psi.KtValueArgumentList
+
+public annotation class Annotation(val name: String)
+
+@Annotation<expr>("y")</expr>
+fun x() {
+
+}