Fix initialization error in WritingSystem (BL-7832)
Fix initialization error in WritingSystem (BL-7832)

IsCustomName should default to false like IsLanguageRTL if the language
is essentially undefined in the .bloomCollection file.

BloomBooks/BloomDesktop,gmartin7/myBloomFork,gmartin7/myBloomFork,gmartin7/myBloomFork,gmartin7/myBloomFork,BloomBooks/BloomDesktop,StephenMcConnel/BloomDesktop,gmartin7/myBloomFork,BloomBooks/BloomDesktop,StephenMcConnel/BloomDesktop,StephenMcConnel/BloomDesktop,gmartin7/myBloomFork,BloomBooks/BloomDesktop,BloomBooks/BloomDesktop,StephenMcConnel/BloomDesktop,StephenMcConnel/BloomDesktop,StephenMcConnel/BloomDesktop,BloomBooks/BloomDesktop