AAPT2: Variety of small fixes to get the build working

- Add option to rename package in AndroidManifest.xml
- Support default versionName and versionCode
- Accept True and False as valid booleans

Change-Id: I400e350b9dcd0fd1c197d1929144299c7823617d
diff --git a/tools/aapt2/io/FileSystem.cpp b/tools/aapt2/io/FileSystem.cpp
index 76f87ae..e758d8a4 100644
--- a/tools/aapt2/io/FileSystem.cpp
+++ b/tools/aapt2/io/FileSystem.cpp
@@ -32,7 +32,10 @@
 std::unique_ptr<IData> RegularFile::openAsData() {
     android::FileMap map;
     if (Maybe<android::FileMap> map = file::mmapPath(mSource.path, nullptr)) {
-        return util::make_unique<MmappedData>(std::move(map.value()));
+        if (map.value().getDataPtr() && map.value().getDataLength() > 0) {
+            return util::make_unique<MmappedData>(std::move(map.value()));
+        }
+        return util::make_unique<EmptyData>();
     }
     return {};
 }