Build: Forbid implicit case fall-through without a comment and enable…

… couple more recommendable error-prone checks (apache#11251)

* Forbid implicit case fall-through without a comment

In ordinary switch statement, case branches implicitly fall-through to
the next one. This is Java's C legacy. Forbid this unless intent is
indicated in the code with a comment like `// fall through`.

* Enable couple more recommendable error-prone checks

baseline.gradle

@@ -83,6 +83,8 @@ subprojects {
           '-Xep:BadComparable:ERROR',
           '-Xep:BadInstanceof:ERROR',
           '-Xep:CatchFail:ERROR',
+          '-Xep:ClassCanBeStatic:ERROR',
+          '-Xep:ClassNewInstance:ERROR',
           '-Xep:CollectionUndefinedEquality:ERROR',
           // specific to Palantir - Uses name `log` but we use name `LOG`
           '-Xep:ConsistentLoggerName:OFF',
@@ -95,8 +97,10 @@ subprojects {
           '-Xep:EqualsUnsafeCast:ERROR',
           '-Xep:EqualsUsingHashCode:ERROR',
           '-Xep:ExtendsObject:ERROR',
+          '-Xep:FallThrough:ERROR',
           // specific to Palantir
           '-Xep:FinalClass:OFF',
+          '-Xep:Finalize:ERROR',
           '-Xep:FormatStringAnnotation:ERROR',
           '-Xep:GetClassOnEnum:ERROR',
           '-Xep:HidingField:ERROR',
@@ -146,10 +150,14 @@ subprojects {
           '-Xep:StringSplitter:ERROR',
           '-Xep:TypeParameterShadowing:OFF',
           '-Xep:TypeParameterUnusedInFormals:OFF',
+          '-Xep:UnicodeEscape:ERROR',
           // Palantir's UnnecessarilyQualified may throw during analysis
           '-Xep:UnnecessarilyQualified:OFF',
+          '-Xep:UnnecessaryLongToIntConversion:ERROR',
+          '-Xep:UnnecessaryMethodReference:ERROR',
           '-Xep:UnusedMethod:ERROR',
           '-Xep:UnusedVariable:ERROR',
+          '-Xep:UseEnumSwitch:ERROR',
       )
     }
   }