Fix double space in include argument

The double space is confusing compdb.go.  compdb.go should be fixed,
but the double space is unnecessary so remove it.

Also make -isystem consistently followed by a space.

Bug: 117124308
Test: m checkbuild
Change-Id: I5ce7530d2ef66be8d8285e252d60a39299984a06

cc/kernel_headers.go

@@ -26,7 +26,7 @@ func (stub *kernelHeadersDecorator) link(ctx ModuleContext, flags Flags, deps Pa
 	if ctx.Device() {
 		f := &stub.libraryDecorator.flagExporter
 		for _, dir := range ctx.DeviceConfig().DeviceKernelHeaderDirs() {
-			f.flags = append(f.flags, "-isystem"+dir)
+			f.flags = append(f.flags, "-isystem "+dir)
 		}
 	}
 	return stub.libraryDecorator.linkStatic(ctx, flags, deps, objs)

cc/llndk_library.go

@@ -144,17 +144,17 @@ func (stub *llndkStubDecorator) link(ctx ModuleContext, flags Flags, deps PathDe
 			timestampFiles = append(timestampFiles, stub.processHeaders(ctx, dir, genHeaderOutDir))
 		}
 
-		includePrefix := "-I "
+		includePrefix := "-I"
 		if Bool(stub.Properties.Export_headers_as_system) {
 			includePrefix = "-isystem "
 		}
 
-		stub.reexportFlags([]string{includePrefix + " " + genHeaderOutDir.String()})
+		stub.reexportFlags([]string{includePrefix + genHeaderOutDir.String()})
 		stub.reexportDeps(timestampFiles)
 	}
 
 	if Bool(stub.Properties.Export_headers_as_system) {
-		stub.exportIncludes(ctx, "-isystem")
+		stub.exportIncludes(ctx, "-isystem ")
 		stub.libraryDecorator.flagExporter.Properties.Export_include_dirs = []string{}
 	}
 

cc/ndk_prebuilt.go

@@ -137,7 +137,7 @@ func (ndk *ndkPrebuiltStlLinker) link(ctx ModuleContext, flags Flags,
 		ctx.ModuleErrorf("NDK prebuilt libraries must have an ndk_lib prefixed name")
 	}
 
-	ndk.exportIncludes(ctx, "-isystem")
+	ndk.exportIncludes(ctx, "-isystem ")
 
 	libName := strings.TrimPrefix(ctx.ModuleName(), "ndk_")
 	libExt := flags.Toolchain.ShlibSuffix()