Update language to comply with inclusive guidance

Update android_app_set to use word install rather than master for
android_app_sets, this better matches the phrasing used for apex_set.

See https://source.android.com/setup/contribute/respectful-code for
reference

Bug: 161896447
Test: m nothing
Change-Id: I429e7f8b16c42c10ad4d9543110f5ce814a893b1
diff --git a/java/app.go b/java/app.go
index 4031cfe..1ede34e 100755
--- a/java/app.go
+++ b/java/app.go
@@ -78,7 +78,7 @@
 
 	properties   AndroidAppSetProperties
 	packedOutput android.WritablePath
-	masterFile   string
+	installFile  string
 	apkcertsFile android.ModuleOutPath
 }
 
@@ -102,8 +102,8 @@
 	return as.packedOutput
 }
 
-func (as *AndroidAppSet) MasterFile() string {
-	return as.masterFile
+func (as *AndroidAppSet) InstallFile() string {
+	return as.installFile
 }
 
 func (as *AndroidAppSet) APKCertsFile() android.Path {
@@ -136,10 +136,10 @@
 func (as *AndroidAppSet) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	as.packedOutput = android.PathForModuleOut(ctx, ctx.ModuleName()+".zip")
 	as.apkcertsFile = android.PathForModuleOut(ctx, "apkcerts.txt")
-	// We are assuming here that the master file in the APK
+	// We are assuming here that the install file in the APK
 	// set has `.apk` suffix. If it doesn't the build will fail.
 	// APK sets containing APEX files are handled elsewhere.
-	as.masterFile = as.BaseModuleName() + ".apk"
+	as.installFile = as.BaseModuleName() + ".apk"
 	screenDensities := "all"
 	if dpis := ctx.Config().ProductAAPTPrebuiltDPI(); len(dpis) > 0 {
 		screenDensities = strings.ToUpper(strings.Join(dpis, ","))
@@ -167,7 +167,7 @@
 
 // android_app_set extracts a set of APKs based on the target device
 // configuration and installs this set as "split APKs".
-// The extracted set always contains 'master' APK whose name is
+// The extracted set always contains an APK whose name is
 // _module_name_.apk and every split APK matching target device.
 // The extraction of the density-specific splits depends on
 // PRODUCT_AAPT_PREBUILT_DPI variable. If present (its value should