Rename sdk field tag "keep" to "ignore"

"ignore" is a better description of the effect that this tag has on the
optimization that is done as part of the sdk snapshot generation.
"keep" implies that something special is done with the field during the
optimization process but actually the optimization process completely
ignores the property, just as it does with unexported fields.

Bug: 248258460
Test: m nothing
Change-Id: Idfdfd87f927d641d4d301cbbde72b463c89155bf
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
index 8b8e1d7..4be1e79 100644
--- a/sdk/sdk_test.go
+++ b/sdk/sdk_test.go
@@ -218,15 +218,15 @@
 }
 
 type testPropertiesStruct struct {
-	name        string
-	private     string
-	Public_Kept string `sdk:"keep"`
-	S_Common    string
-	S_Different string `android:"arch_variant"`
-	A_Common    []string
-	A_Different []string `android:"arch_variant"`
-	F_Common    *bool
-	F_Different *bool `android:"arch_variant"`
+	name          string
+	private       string
+	Public_Ignore string `sdk:"ignore"`
+	S_Common      string
+	S_Different   string `android:"arch_variant"`
+	A_Common      []string
+	A_Different   []string `android:"arch_variant"`
+	F_Common      *bool
+	F_Different   *bool `android:"arch_variant"`
 	EmbeddedPropertiesStruct
 }
 
@@ -244,30 +244,30 @@
 	common := &testPropertiesStruct{name: "common"}
 	structs := []propertiesContainer{
 		&testPropertiesStruct{
-			name:        "struct-0",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "common",
-			S_Different: "upper",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string{"alpha", "beta"},
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: proptools.BoolPtr(false),
+			name:          "struct-0",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "common",
+			S_Different:   "upper",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string{"alpha", "beta"},
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   proptools.BoolPtr(false),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "embedded_upper",
 			},
 		},
 		&testPropertiesStruct{
-			name:        "struct-1",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "common",
-			S_Different: "lower",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string{"alpha", "delta"},
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: proptools.BoolPtr(true),
+			name:          "struct-1",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "common",
+			S_Different:   "lower",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string{"alpha", "delta"},
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   proptools.BoolPtr(true),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "embedded_lower",
@@ -282,15 +282,15 @@
 
 	android.AssertDeepEquals(t, "common properties not correct",
 		&testPropertiesStruct{
-			name:        "common",
-			private:     "",
-			Public_Kept: "",
-			S_Common:    "common",
-			S_Different: "",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string(nil),
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: nil,
+			name:          "common",
+			private:       "",
+			Public_Ignore: "",
+			S_Common:      "common",
+			S_Different:   "",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string(nil),
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   nil,
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "",
@@ -300,15 +300,15 @@
 
 	android.AssertDeepEquals(t, "updated properties[0] not correct",
 		&testPropertiesStruct{
-			name:        "struct-0",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "",
-			S_Different: "upper",
-			A_Common:    nil,
-			A_Different: []string{"alpha", "beta"},
-			F_Common:    nil,
-			F_Different: proptools.BoolPtr(false),
+			name:          "struct-0",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "",
+			S_Different:   "upper",
+			A_Common:      nil,
+			A_Different:   []string{"alpha", "beta"},
+			F_Common:      nil,
+			F_Different:   proptools.BoolPtr(false),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "",
 				S_Embedded_Different: "embedded_upper",
@@ -318,15 +318,15 @@
 
 	android.AssertDeepEquals(t, "updated properties[1] not correct",
 		&testPropertiesStruct{
-			name:        "struct-1",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "",
-			S_Different: "lower",
-			A_Common:    nil,
-			A_Different: []string{"alpha", "delta"},
-			F_Common:    nil,
-			F_Different: proptools.BoolPtr(true),
+			name:          "struct-1",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "",
+			S_Different:   "lower",
+			A_Common:      nil,
+			A_Different:   []string{"alpha", "delta"},
+			F_Common:      nil,
+			F_Different:   proptools.BoolPtr(true),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "",
 				S_Embedded_Different: "embedded_lower",