ART tests: do not retrieve OatQuickMethodHeader for bridge methods

Some ART tests (e.g. 604-hot-static-interface) call
OatQuickMethodHeader::FromEntryPoint() for a method's quick compiled
code entry. If the entry has not been set to a compiled code then it
can be set to art_quick_to_interpreter_bridge. This method does not
have a OatQuickMethodHeader and FromEntryPoint() must not be called.

This patch fixes ART tests to retrieve OAT header only for methods
that reside in the JIT code cache.

Change-Id: I21105735f146e6c67c24c970a42451e3300c067c
Test: test-art-host-run-test-debug-prebuild-jit-relocate-ntrace-cms-checkjni-picimage-npictest-ndebuggable-604-hot-static-interface32
Signed-off-by: Yevgeny Rouban <yevgeny.y.rouban@intel.com>