Remove coverage variants of vndk_prebuilt_shared

vndk_prebuilt_shared is also one of prebuilt modules, so coverage
variants shouldn't be created.

Bug: 128524141
Test: m NATIVE_COVERAGE=true COVERAGE_PATHS=*
Change-Id: I586651c6775a6ae23dc0412ec5538eefd8e92dde

cc/vndk_prebuilt.go

@@ -139,6 +139,10 @@ func (p *vndkPrebuiltLibraryDecorator) link(ctx ModuleContext,
 	return nil
 }
 
+func (p *vndkPrebuiltLibraryDecorator) nativeCoverage() bool {
+	return false
+}
+
 func (p *vndkPrebuiltLibraryDecorator) install(ctx ModuleContext, file android.Path) {
 	arches := ctx.DeviceConfig().Arches()
 	if len(arches) == 0 || arches[0].ArchType.String() != p.arch() {