Remove customizableProperties from android.ModuleBase

- customizableProperties was being used to access all properties,
i.e. basically `GetProperties()`

- generalProperties was a subset of properties,
i.e. `initArchModule()` would only add new arch-specific properties
to `customizableProperties` (and `archProperties`) but not `generalProperties`

This PR sets generalProperties to contain all properties,
which then makes customizableProperties redundant.
And in arch.go, any iteration is done via `archProperties` instead.

Bug: 206961391
Test: m nothing and diff the ninja files
Change-Id: Ieb72b31c0a447fcbf34c92a04f002d7b9d777a86

android/module.go

@@ -1033,7 +1033,6 @@ func InitAndroidModule(m Module) {
 	initProductVariableModule(m)
 
 	base.generalProperties = m.GetProperties()
-	base.customizableProperties = m.GetProperties()
 
 	// The default_visibility property needs to be checked and parsed by the visibility module during
 	// its checking and parsing phases so make it the primary visibility property.
@@ -1217,8 +1216,6 @@ type ModuleBase struct {
 	// filled with arch specific values by the arch mutator.
 	archProperties [][]interface{}
 
-	customizableProperties []interface{}
-
 	// Properties specific to the Blueprint to BUILD migration.
 	bazelTargetModuleProperties bazel.BazelTargetModuleProperties