Enable clang-tidy for sensitive domain.

Since installd has broad access to lots of sensitive data, enable
as many security-related tidy checks as possible to help avoid bugs.

This change provides a default implementation of create_cache_path(),
calculate_odex_file_path(), and calculate_oat_file_path(), along
with tests to verify behavior against old code.

Replace "dir_rec_t" with std::string, since that's really what it's
been all along.  Increase paranoia of path checking to reject any
paths containing "..", regardless of where it occurs in path string.
Stricter checking of instruction set values.

Remove now-unused char* manipulation utility methods; people should
be using std::string instead.

Test: adb shell /data/nativetest/installd_cache_test/installd_cache_test
Test: adb shell /data/nativetest/installd_service_test/installd_service_test
Test: adb shell /data/nativetest/installd_utils_test/installd_utils_test
Bug: 36655947
Change-Id: Ib706f0b8c1878be64710c00f56dccdfbe215570f