drawables have no declaration in the base drawable folder or in a drawable-densitydpi

**Description:**
I have a published app which i needed to make a few changes and re-publish. When i try to build now i get numerous errors of the type:
Error: The drawable "screen" in drawable-land-hdpi has no declaration in the base drawable folder or in a drawable-densitydpi folder; this can lead to crashes when the drawable is queried in a configuration that does not match this qualifier [MissingDefaultResource]

**Steps to Reproduce:**
ionic cordova resources android
ionic cordova build android --prod --release

**Output:**
numerous errors like:
Error: The drawable "screen" in drawable-land-hdpi has no declaration in the base drawable folder or in a drawable-densitydpi folder; this can lead to crashes when the drawable is queried in a configuration that does not match this qualifier [MissingDefaultResource]

**My `ionic info`:**
Ionic:

Ionic CLI : 5.4.13 (C:\Users\Peter\AppData\Roaming\npm\node_modules\ionic)
Ionic Framework : @ionic/angular 4.12.0-dev.201910171955.51969ca
@angular-devkit/build-angular : 0.13.9
@angular-devkit/schematics : 7.3.9
@angular/cli : 7.3.9
@ionic/angular-toolkit : 1.5.1

Capacitor:

Capacitor CLI : 1.0.0-beta.24
@capacitor/core : 1.0.0-beta.24

Cordova:

Cordova CLI : 9.0.0 (cordova-lib@9.0.1)
Cordova Platforms : android 8.0.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.0.1, (and 8 other plugins)

Utility:

cordova-res (update available: 0.8.0) : 0.3.0
native-run (update available: 0.2.9) : 0.2.8

System:

Android SDK Tools : 26.1.1 (C:\android-sdk)
NodeJS : v10.13.0 (D:\Program Files\nodejs\node.exe)
npm : 6.13.4
OS : Windows 7

**Other Information:**
I published this app back in early Sept and everything worked.

Begin with `ionic cordova resources android` and `ionic cordova build android --prod --release`, then inspect the generated drawable resources and the `MissingDefaultResource` output. Done means identifying whether resource generation or the Android build inputs cause the missing base declarations and documenting a reproducible fix.

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