You can add it to /string.xml with the flag translatable = "false"
<string name="facebook_app_id" translatable="false">YOUR_FACEBOOK_APP_ID</String>
Or you can add FACEBOOK_APP_ID to your gradle file using resValue or buildConfigField . Something like that:
buildTypes { debug { buildConfigField "string", "facebook_app_id1", "YOUR_FACEBOOK_APP_ID" resValue "string", "facebook_app_id", "YOUR_FACEBOOK_APP_ID" } release { minifyEnabled true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' buildConfigField "string", "facebook_app_id1", "YOUR_FACEBOOK_APP_ID" resValue "string", "facebook_app_id", "YOUR_FACEBOOK_APP_ID" } }
Customs:
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