remove ambiguities in pounds per gallon abbreviations

Author: heytherefred

UnitsNet/GeneratedCode/UnitSystem.Default.g.cs

@@ -800,12 +800,12 @@ private static readonly ReadOnlyCollection<UnitLocalization> DefaultLocalization
                         new CulturesForEnumValue((int) DensityUnit.PoundPerImperialGallon,
                             new[]
                             {
-                                new AbbreviationsForCulture("en-US", "ppg"),
+                                new AbbreviationsForCulture("en-US", "ppg (imp.)"),
                             }),
                         new CulturesForEnumValue((int) DensityUnit.PoundPerUSGallon,
                             new[]
                             {
-                                new AbbreviationsForCulture("en-US", "ppg"),
+                                new AbbreviationsForCulture("en-US", "ppg (U.S.)"),
                             }),
                         new CulturesForEnumValue((int) DensityUnit.SlugPerCubicFoot,
                             new[]

UnitsNet/UnitDefinitions/Density.json

@@ -170,7 +170,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "ppg" ]
+          "Abbreviations": [ "ppg (U.S.)" ]
         }
       ]
     },
@@ -182,7 +182,7 @@
       "Localization": [
         {
           "Culture": "en-US",
-          "Abbreviations": [ "ppg" ]
+          "Abbreviations": [ "ppg (imp.)" ]
         }
       ]
     }