AAPT2: include package name in styleable children

When writing partial R files, also include the package of the styleable
child:
<declare-styleable name="ds1">
    <attr name="font"/>
    <attr name="android:font"/>
    <attr name="tools:font"/>
    <attr name="com.foo.bar:font"/>
</declare-styleable>
will produce:
default int styleable ds1_font
default int styleable ds1_android_font
default int styleable ds1_tools_font
default int styleable ds1_com_foo_bar_font

Bug: 73927419
Test: manual, see description
Change-Id: Ica493408c7c6d9e7fae2b693c96fbc20a723ce08
diff --git a/tools/aapt2/cmd/Util.h b/tools/aapt2/cmd/Util.h
index 7611c15..fb8753e 100644
--- a/tools/aapt2/cmd/Util.h
+++ b/tools/aapt2/cmd/Util.h
@@ -60,6 +60,13 @@
 Maybe<AppInfo> ExtractAppInfoFromBinaryManifest(const xml::XmlResource& xml_res,
                                                 IDiagnostics* diag);
 
+// Returns a copy of 'name' which conforms to the regex '[a-zA-Z]+[a-zA-Z0-9_]*' by
+// replacing nonconforming characters with underscores.
+//
+// See frameworks/base/core/java/android/content/pm/PackageParser.java which
+// checks this at runtime.
+std::string MakePackageSafeName(const std::string &name);
+
 }  // namespace aapt
 
 #endif /* AAPT_SPLIT_UTIL_H */