Revert^2 "Fix erroneous "Field requires API level 33 (current min is 32)" warnings"

This reverts commit 5d80d895b6.

Reason for revert: The issue that broke the build the first time this was submitted has been fixed in ag/19125702. Also the errorprone build was added to presubmit for changes to these files so we should hopefully catch any other issues at presubmit now: cl/458501206

Change-Id: I80ca08df49c58a1ad70de917822301368d49fc67

android/api_levels.go

@@ -54,6 +54,14 @@ type ApiLevel struct {
 	isPreview bool
 }
 
+func (this ApiLevel) FinalInt() int {
+	if this.IsPreview() {
+		panic("Requested a final int from a non-final ApiLevel")
+	} else {
+		return this.number
+	}
+}
+
 func (this ApiLevel) FinalOrFutureInt() int {
 	if this.IsPreview() {
 		return FutureApiLevelInt