Remove obsolete Brillo variable

Unlike the original change on master, this does not remove
product_variables.brillo, as I'm not backporting all of the other
removal CLs.

Bug: 76168832
Test: none
Change-Id: I6a5ce57b317f0cdae1abef15def01e6a31e18d3e
Merged-In: I6a5ce57b317f0cdae1abef15def01e6a31e18d3e
(cherry picked from commit a052599bb6)

cc/compiler.go

@@ -377,10 +377,6 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps
 			fmt.Sprintf("${config.%sGlobalCflags}", hod))
 	}
 
-	if Bool(ctx.Config().ProductVariables.Brillo) {
-		flags.GlobalFlags = append(flags.GlobalFlags, "-D__BRILLO__")
-	}
-
 	if ctx.Device() {
 		if Bool(compiler.Properties.Rtti) {
 			flags.CppFlags = append(flags.CppFlags, "-frtti")

cc/makevars.go

@@ -211,9 +211,6 @@ func makeVarsToolchain(ctx android.MakeVarsContext, secondPrefix string,
 		hod = "Device"
 	}
 
-	if target.Os.Class == android.Device && Bool(ctx.Config().ProductVariables.Brillo) {
-		productExtraCflags += "-D__BRILLO__"
-	}
 	if target.Os.Class == android.Host && Bool(ctx.Config().ProductVariables.HostStaticBinaries) {
 		productExtraLdflags += "-static"
 	}