Add more CTS tests error prone rules

EqualsNan, prevent comparing to Float.NaN that always yield
false. Using isNaN instead.

ArrayToString is pending b/37995059 to handle external/
changes to fix warnings.

FormatString to make sure the print will be as expected.

Test: make cts javac-check -j76 TARGET_PRODUCT=aosp_arm64
WITH_DEXPREOPT=false RUN_ERROR_PRONE=true
Bug: 37854485

Change-Id: I916b77e4821fb5b860e2704180b5b290ff633138
15 files changed